Dave Plummer went through this while at Microsoft. He had a product he was selling (a shell extension to handle ZIP files) and got a call out of the blue from a M&A person at Microsoft wanting to talk about purchasing it. It got strange when he told them he would walk over to their office to discuss it.

He said he pretty much took their first offer as he didn't want to endanger his position at the company.

https://www.youtube.com/watch?v=4j0yI41e0j4