Mascots can be beneficial. Look at Geico. For decades they've used the Gecko as their mascot, and it's hard to think of Geico without thinking of the Gecko, the "It's so easy a caveman can do it" branding or the "who's watching you" and the two eyes on the money.
Millions are spent to brand this into your brain, and it works!
Cartoon characters apeal to a certain demographic, it just all depends if you want to limit yourself to that demographic. This is why you'll find many hosting companies set up multiple websites with different targets in mind.
And I'm with Zachary on the make or break issue. The wrong name can send the wrong message, but with enough money you can USUALLY turn a brand.