" I assume the disadvantage is that you need to do a lot more brand marketing for such names. What's your opinion? "

With domain names like that, I think what they're trying to do is use creative names to imbed into your minds so you won't forget. Who wants to use a search engine called "Finders!" Instead of Google. Google sounds more interesting and more people would want to flock to it just to see what it's about.

When I first heard of Dogpile.com, I had to go see what it was. It's a very good search engine, by the way.

Creative name - can't forget it.