I agree with this. This is why I still do the occasional 'discovery call' with people directly involved in a project -- and is very clearly communicated as not being a sales call.

One of the most infuriating b2b calls I've ever been on was setup by our vendor to sound like this. After almost a year of using their product (on a month to month plan), they wanted to check-in and see what features we were using, what we liked, didn't like and show us the new stuff they'd released etc. And then in the last 10 minutes of an hour long call, they dropped a little "we just need to go over some administrative details" bomb where they started negotiations to get us on a year long contract. I will never accept another discovery call from this vendor again. It was such a huge piss off.