B2B buyers: the rule of thirds and 10 channels per purchase

The B2B buyer of 2026 splits the buying journey into three parts of similar size: one third prefers in-person meetings, one third prefers remote conversations with the supplier and one third prefers to handle things alone, through digital self-service. McKinsey calls this pattern the rule of thirds and confirmed it once again in the 2026 Global B2B Pulse, published in May, with answers from nearly 4,000 B2B decision makers in 13 countries. In the same survey, buyers use ten channels on average across the journey and expect to move between them without friction. I read these numbers as a change in the seller’s job: the seller is still present in two of the three thirds and is no longer the entry point for information. The customer reaches the conversation after reading the website, comparing suppliers and asking an AI tool, and the seller adds value at the moments when the buyer needs help to decide. The website, content and CRM carry the rest of the journey, and when each one tells a different story, the buyer notices and switches suppliers.

At Iasbeck&Co we implement CRM and AI agents in B2B operations and train sales teams, and the question I hear most from boards on this subject is whether it still makes sense to hire salespeople. The research says yes, with a different profile and a different structure around them. I wrote this for the board, sales, marketing and customer success leaders, and HR.

How do B2B buyers buy today, according to the research?

McKinsey asks decision makers how they prefer to interact at each stage, Gartner asks buyers about a recent purchase, and Forrester describes the buying group and what it does to reduce risk. The numbers complement each other, as long as you look at the question each one asked.

Source	Year	Sample and method	Main finding
McKinsey, Global B2B Pulse	2026	Nearly 4,000 B2B decision makers in 13 countries and several sectors; historical series with a wave in December 2025	Rule of thirds holds; ten channels on average; 73% are comfortable placing orders above US$50,000 online, versus 59% in 2022
McKinsey, B2B Pulse	2024	Nearly 4,000 decision makers in 34 sectors and 13 countries; ninth edition of the survey	41% prefer in-person with a new supplier; more than half are likely to switch suppliers if the cross-channel experience fails
Gartner	2020	Forecast from the Future of Sales research; the release gives no sample	80% of B2B sales interactions would happen in digital channels by 2025
Gartner	2022	725 B2B buyers, November to December 2021	24% of seller-led purchases ended in a high-quality deal, versus 65% of buyer-led purchases
Gartner	2025	632 B2B buyers, August to September 2024	69% saw inconsistent information between the website and the seller; 73% avoid suppliers who send irrelevant outreach
Forrester, The State Of Business Buying, 2026	2026	Annual report in the Buyer Insights series; the release does not publish the sample	More than 60% of buyers use some kind of trial before buying, and 78% for purchases of US$10 million or more

What is McKinsey’s rule of thirds?

The rule of thirds describes the buyer’s preference among three forms of interaction: in person, remote with someone from the supplier, such as video calls and phone, and digital self-service, where the buyer researches and buys without talking to anyone. In the 2024 edition, McKinsey states that at any stage of the journey one third of customers want in-person, one third remote and one third self-service, across countries, sectors and company sizes, in new purchases and repeat purchases.

Before 2020, about half of respondents preferred in-person contact to research and evaluate suppliers, and the split became even after the pandemic cut face-to-face meetings. In the 2026 edition, the firm records a slow movement inside the balance: digital self-service gains interest little by little and remote human interaction loses it, and McKinsey expects digital to grow as AI takes over follow-ups and contacts that do not involve an order.

In-person matters where the purchase takes effort

In 2024, 41% of respondents preferred in-person channels when dealing with a new supplier, and 40% when buying something for the first time. The 2026 edition adds a practical rule: with many transactions, buyers prefer self-service, and with large, infrequent orders they prefer human interaction, even on reorders. In projects and annual contracts the seller stays at the center of the decision, and in low-value replenishment the portal does much of the work.

Three buyer profiles in the same portfolio

McKinsey groups respondents into three profiles, present in every country and sector of the sample. Adapters value the relationship and tend to stay with the supplier they know, seekers demand integration across channels and switch suppliers when it fails, and innovators adopt technology early, including generative AI to research suppliers.

Profile (McKinsey)	2024	2026	Willing to transact US$500,000 or more without meeting, 2024	Same question, 2026
Adapters (relationship oriented)	44%	53%	19%	18%
Seekers (demand omnichannel)	36%	29%	69%	61%
Innovators (early tech adopters)	20%	18%	37%	29%

In 2024 the question was about remote transactions and in 2026 about buying new products online. The figure that stands out to me is the growth of adapters, from 44% to 53% in two years, and McKinsey itself suggests that the pace of technological change may be reinforcing the value of trusted relationships.

How much will a B2B buyer spend without talking to anyone?

In 2022, 59% of McKinsey’s respondents were comfortable placing orders above US$50,000 online, and in 2026 that figure reached 73%. For US$500,000 or more, willingness fell five percentage points compared with 2024, a drop the firm attributes to economic caution. On the selling side, 71% of respondents say their company offers e-commerce, and in those companies roughly one third of revenue flows through digital channels, which makes digital the top revenue channel. In 2024, in-person sales had fallen five points, to 17% of revenue.

These numbers describe companies that sell products with a catalog and a price. For those who sell tailored projects, what matters is the behavior behind the data: buyers already do much of the research and comparison on their own, including at high values.

Did Gartner’s 80% digital prediction come true?

In September 2020, Gartner announced that, according to its Future of Sales research, 80% of B2B sales interactions between suppliers and buyers would take place in digital channels by 2025. The release supported the forecast with two numbers: 33% of buyers wanted a seller-free sales experience, a preference that rose to 44% among millennials, and buyers spent only 17% of their purchase time meeting with suppliers. The text gives no sample or method for the projection, and the full report is restricted to clients.

The 80% figure still circulates in presentations as if it were a measurement. I looked on Gartner’s website for a release that checked the prediction after 2025 and did not find one, and the surveys the firm published later measured the preference for buying without a seller and the quality of purchases.

McKinsey offers the closest comparison, and the definition of channel changes the conclusion. Adding the remote third to the self-service third, you get about two thirds of interactions outside in-person meetings, and part of the remote ones happen by video and phone with a seller on the other side. If Gartner counted video calls as a digital channel, the forecast got the direction right and overstated the size. If it counted only self-service, it was far off, because that third is still a third. Either way, in-person meetings remain around one third of preferences, well above the 20% the forecast would leave for other channels.

Why do B2B buyers switch suppliers?

In 2024, more than half of McKinsey’s respondents said they would likely look for another supplier if the cross-channel experience was not smooth, and among seekers the figure reached 65%. The reasons cited were a poor digital experience (54%), lack of customer tracking across channels (51%) and not being connected to the right person (51%). In 2026, the top reason became inconsistent information across the supplier’s teams, followed by difficulty reaching someone knowledgeable, with cross-channel tracking gaps in third place.

Gartner measured the same problem from the buyer’s side. In the survey of 632 B2B buyers released in 2025, 69% reported inconsistencies between the information on the supplier’s website and what the seller told them, and 73% said they avoid suppliers who send irrelevant outreach. The analyst quoted in the release recommends synchronizing the website with the sales message, because the inconsistency creates mistrust and puts the purchase at risk.

Both findings describe an operational failure. The buyer reads one scope on the website, hears another from the seller and gets a third version from customer success, because in many companies marketing writes the website, sales builds its own deck and nobody records in the CRM what was promised. The agreement between teams on message and records is the subject of marketing and sales alignment.

Where does the seller still make a difference in the B2B buying journey?

Gartner’s 2025 release has the most useful answer for sales leaders. Buyers prefer self-service to look for general information and learn new things, and prefer the seller for tasks that require context, such as deciding whether the solution fits their company’s needs. Across all stages, they prefer to complete on average 3.0 activities combining digital and the seller, 2.3 with the seller only and 1.8 through self-service only. The latest edition of the preference for buying without a seller is in Challenger Sale.

The seller who repeats the website makes the purchase worse

Gartner’s survey of 725 buyers, conducted in late 2021, shows the risk on both sides. Only 24% of buyers in seller-led purchases completed a high-quality deal, versus 65% of those who navigated the purchase themselves, and digital commerce buyers reported regret more often than traditional buyers. Gartner attributes both failures to shallow customer learning: the website makes it easy to follow through on a misguided decision, and the seller oversimplifies the recommendation and pushes the buyer forward without a full understanding of their own needs.

According to the same release, buyers who go through a learning path that combines digital and people, with room to reflect on their own situation, are 147% more likely to buy more than they planned. I see here the central argument for consultative selling: the seller who diagnoses helps the buyer understand the problem, and the one who presents the catalog competes with the website and loses.

AI at the start of the search, people for validation

In The State Of Business Buying, 2026, Forrester describes generative AI search as the buyer’s starting point, with answer engines that deliver speed and information that is often incomplete or unreliable. Buyers compensate by seeking validation from trusted people inside and outside the company, and 94% of those buying with groups of six or more report benefits from the large group, such as a better chance of approval, a subject covered in B2B buying committee.

The same report shows trials as a way to reduce risk: more than 60% of B2B buyers use some kind of trial to evaluate solutions, and 78% of those making purchases of US$10 million or more run a trial first. In services, the equivalent is a pilot with agreed success criteria or a paid diagnostic, and the path to signature can become a mutual action plan.

What changes for content, website and CRM?

The website and content handle the first contact, and the CRM keeps the memory that lets the seller pick up the conversation where the customer left off. The table links each finding to what I see working in the operations I serve; the last column is my own reading, and the research did not test these practices.

Finding	Source	What the operation does
One third prefer self-service at any stage	McKinsey, 2024 and 2026	Website with scope, timeline, investment range and cases by segment, so the buyer can move forward without asking for a meeting
Buyers use ten channels on average	McKinsey, 2026	Every interaction recorded in the CRM, so the seller knows what the customer has seen before calling
Inconsistent information is the top reason to switch	McKinsey, 2026	A single source for message, scope and price, reviewed by marketing and sales and used by customer success
69% see inconsistencies between website and seller	Gartner, 2025	Deck, proposal and website with the same offer description, reviewed together when the offer changes
Sellers are preferred to decide whether the solution fits	Gartner, 2025	First meeting dedicated to diagnosis, without repeating the website presentation
73% avoid irrelevant outreach	Gartner, 2025	Prospecting with account research and a concrete reason for contact, recorded in the CRM
More than 60% run trials before buying	Forrester, 2026	Pilot or diagnostic with written success criteria, tracked as a pipeline stage

Without the history of pages visited, materials downloaded and seller promises in the CRM, every person at the supplier starts the conversation from scratch, and the buyer feels the lack of tracking that McKinsey lists among the reasons to switch. The recording and deduplication rules that support that history are in CRM data quality.

What this data does not tell us

McKinsey’s e-commerce questions treat the respondent’s company as the seller, in a group that tends to sell standardized products. The public page does not detail how the sample was recruited or its distribution by country, and Brazil does not appear separately.

Almost everything is self-reported. Stated preference may differ from behavior, because buyers accept the meeting they say they do not want when the purchase is expensive. Gartner measures recent purchases from memory, and the high quality of a deal is the buyer’s own assessment. Forrester does not publish the sample in the release, and the percentages on trials and groups serve as direction.

The 80% forecast is a projection, and no public source I found measured whether it came true. Comparing it with the rule of thirds requires choosing a definition of digital channel, and the conclusion changes with the definition.

None of these studies proves causation. Seller-led purchases may end worse because they are the hardest ones, those in which the buyer felt the need to call someone.

What leadership does with these numbers

The roadmap below fits in a quarter and starts with the data the company already has.

1. Find out which third your customer is in at each stage. Use the CRM and website analytics to see how many deals started from a form, a referral or prospecting, and at which stage the customer asked for the first meeting. Separate new purchases from repeat purchases.
2. Map the channels buyers use with your company. List website, email, WhatsApp, video, events and support, and check which ones record the interaction in the CRM. A channel without records is the blind spot of the journey.
3. Unify the message. Put website, deck, proposal and customer success material side by side, fix the inconsistencies and define who approves each change to the offer.
4. Redesign the first meeting. If the website already explains the company, the meeting starts with diagnosis and ends with an agreed next step, and the manager checks it in the CRM.
5. Offer a form of trial with criteria. Define the pilot, paid diagnostic or proof of concept that makes sense for your offer, with a written timeline and success criteria.
6. Measure the new behavior. Track first-meeting conversion, the share of deals with a recorded diagnosis and loss reasons, and review in 90 days.

What HR and L&D need to consider

If customers learn on their own what is on the website, sellers need to diagnose, read the customer’s business and lead a group with different goals to a decision, skills that product training does not develop. HR recognizes the need in signals from the CRM and loss reviews: first meetings that turn into presentations, proposals that repeat the catalog and deals lost to “we decided not to do anything now”. Training works better when it brings sales, marketing and customer success together, because the inconsistency the buyer perceives starts in the handoffs between these teams, and the effect shows up in first-meeting-to-proposal conversion.

A buyer who splits the journey into thirds expects to find, in the third that has a seller, someone who adds what the website does not offer. Developing that seller is the work of the in-company consultative selling training, built on the company’s customers, offers and CRM, with sales, marketing and customer success leaders in the room. It delivers the consultative selling playbook, with what the seller does and records at each stage, and the needs discovery framework, which turns the first meeting into a diagnosis.

Frequently asked questions

What is the rule of thirds in B2B sales?

It is the pattern McKinsey has found in the B2B Pulse since the pandemic: at any stage of the journey, about one third of buyers prefer in-person interaction, one third prefer remote interaction with the supplier and one third prefer digital self-service. The 2026 edition, with nearly 4,000 decision makers from 13 countries, confirmed the pattern, with self-service gaining interest little by little.

Is it true that 80% of B2B sales interactions are already digital?

The number comes from a 2020 Gartner forecast for 2025, not from a measurement. I did not find a public Gartner release that checks the forecast. In McKinsey’s 2026 survey, in-person meetings remain the preference of about one third of buyers.

Do B2B buyers still want to talk to a seller?

Yes, at specific moments. In the Gartner survey released in 2025, buyers prefer self-service for general information and the seller to decide whether the solution fits their company. In McKinsey’s 2024 survey, 41% preferred in-person contact when dealing with a new supplier.

How many channels does a B2B buyer use in a purchase?

Ten on average, according to McKinsey’s 2026 survey, with supplier websites, in-person meetings, web search, videoconferencing and generative AI among the top five channels for discovery and evaluation. In 2016, the same series recorded five channels on average.

Why do B2B customers switch suppliers?

In McKinsey’s 2026 survey, the top reason is inconsistent information across the supplier’s teams, followed by difficulty reaching someone knowledgeable and cross-channel tracking gaps. In Gartner’s survey, 69% of buyers reported inconsistencies between the website and the seller.

How do you prepare the sales team for the digital buyer?

Train diagnosis, because customers arrive informed and expect the seller to help them decide whether the solution fits. Bring sales, marketing and customer success into the same program to align message, scope and CRM records, and have managers check the first meeting as part of their routine.