A brazen question of a tagline, not just because of the presence of a an exclamation mark! It’s open to a blunt disengagement by two letters, NO!
As a result this is a weak tagline in my opinion, trying to make the word Yahoo an actual doing word, like Yahooing.
If asking a question make it count, inviting people to Yahoo with a line such as “Come Yahoo!?” would be a better aligned statement and softer question, in my view.
More Boohoo than Yahoo, 2/5 from me.