It's because bit.ly shows all clicks, not including duplicates. Mylikes doesn't count duplicate clicks. Also Mylikes pays most from clicks from America, and far less for other countries. So that also plays a big role in your pay from the amount of clicks you made. When you're on bitly, go the stats and pay attention only to the amount of U.S clicks you get and use that as a reference to how Mylikes shows your clicks. Basically, mylikes focuses primarily on U.S traffic. hope that makes sense.