Twitter can't really stop them. If I tweet out "I love Pepsi" twitter doesn't really know if I was paid to say that or not. The existence of the "(ad)" part of

Twitter can't really stop them. If I tweet out "I love Pepsi" twitter doesn't really know if I was paid to say that or not. The existence of the "(ad)" part of the tweet is just a courtesy. Selling out is probably as old as society. :-) They could try to block ad.ly from the API which I assume they use to get metrics about users, but ad.ly could just then buy those metrics from some other company or scrape them themselves.