“Similar” domain names

I keep getting emails that look something like this one that I received this morning:

My name is Marcus and I have found that you hold a similar domain name. That said, I am wondering if you could perhaps benefit in getting the kassoff dot com ?

I don’t consider Kasson and Kassoff to be similar names. But the persistent emails have gotten me thinking. Do you suppose that the financial company that is the holder of the domain name jackson.com is getting emails offering him the “similar” name of , well, you get the idea?