It's very useful for b2b people to know who is looking at your website and who might be good targets to reach out to. Knowing that Steve the SVP at Databricks is looking at your website vs cookie 1234 is a pretty key differentiator
From first-hand experience, B2B sellers do not get this information today. They typically get "signals" like "Company X is searching for product category Y" or "Company X is visiting your web site". And "Company X's CIO is John Smith - here's his phone number". But nobody that I've seen claims to offer individual names of web site visitors.
Services like retention.com provide email addresses for otherwise anonymous site visitors based on information provided to them by their "publisher network".
There are a lot of companies selling exactly this service. In some cases, they're able to do it pretty easily, because most people don't actually make any effort whatsoever to remain anonymous. And in a B2B setting, there's a good chance your own company is feeding their data into the same pool.
Some companies are trying to sell you on "AI based" solutions that take deanonymization a step further, but as far as I can tell, it's mostly horseshit and wishful thinking.
What I mean is that they provide enough information to pair your first-party data with "anonymous" web traffic matched to the account level with enough granularity to line up the two.
That said, most of the companies in this space massively over promise and under deliver. The one thing they all have in common is that they're good at ABM, so they can sell to your CMO/CRO faster than you can call them out on their bullshit.
