Planet13 - 3:43 pm on Jan 30, 2012 (gmt 0)
I would say report them.
If you site is clean (I am assuming it is), then why not?
Yeah, some people might call you names that are usually brandied about by third graders. They are (probably) the same types of people who regularly buy links, which would explain there disdain for those who would like to see the google SERPs free of spam.
You WOULD be creating a benefit for users, because honestly, they don't want their search results cluttered with the same companies over and over again.
And also, if you report them and NOTHING happens, well, at least you will know what you can get away with in the future should you decide to emulate them :)