[staunch]

Reall Freaking Big One: Effective advertising.

It's still very much an unsolved problem. Google figured out their end of it, but the end-user is still left out in the cold. Ask anyone who uses AdWords if they think it's an intuitive or pleasant experience.

There are other kinds of advertising ripe for disruption too. A lot of people have money coming online and it's surprisingly hard to spend it effectively.

[bmh100]

staunch13, this is a very fascinating area for me as well, and I am looking to disrupt it. What is your biggest frustration?