I took my Linkshare affiliate link and shortened it via url shortener bit.ly

When I check the bit.ly link in a browser it does resolve to the correct affiliate link.

Now when I look at my Linkshare stats it tells me:
Quick Stats (Last 7 Days - US Network): 261

When I look at the bit.ly stats I get this number of clicks: 29

So I have 261 clicks on one hand and 29 clicks on the other hand. How does this fit together?

Plz help a newbie