As someone who lives on the cape, I'll say that even though there seems to be lot of stations - they must be doing ok as the quality of programming is pretty good. Most of the music stations I would prefer over similiarly formatted Boston stations. Heck, Boston doesn't even have two commercial stations with in house newsrooms, but the cape does (WQRC and WXTK) and they have some amazingly dedicated and good reporters/anchors for a small market.
Most of the Boston stations don't come in all that well on the cape so there is definitely an opportunity being filled.
Yes, there are a lot of ads for tourist type destinations - especially restaurants.