When dealing with unique trademarks, it's easier for the owner of the mark to assert that a use by a service that does not directly compete with it is still an infringement, because it suggests an association or sponsorship, and could subject their mark to dilution. Microsoft can use that argument against "Microsoft Babysitting Service", but things change for trademarks based upon ordinary words in an ordinary combination, or where the mark is an actual name. McDonalds has had to litigate with a number of people named "McDonald" or "MacDonald" over their sometimes all-too-cute efforts to leverage the McDonald's brand. ("Our 'Big Mac' is named after our son, Mackenzie - that's his nickname.") Wendy's, the fast food chain, would have no luck shutting down "Wendy's Babysitting Service".