One of the things I like about twitter is the short form blogging. One of the things I don't like is having a twitter client distract me every few minutes (so I don't use one) or if I use the site instead, having to flip through a couple of pages of noise to find the little gems contained within.
I think a compendium of tweets would compile these two aspects of twitter, yet also give twitter the ability to make revenue off my attention.
my 2 cents.
Fortunately, it hasn't caught on. There isn't much incentive to sign up; advertising makes you look like a tool, the money available is bound to be small, Twitter in general doesn't incur overhead, and people mostly use Twitter for fun.
Perhaps Twitter make it against the TOS, but even that seems overkill. The "viral" nature of Twitter should keep the negative effects of advertising to a minimum.