Click Bots on Twitter

How many click bots are present on Twitter?

Today I shared a link through su.pr; the new StumbleUpon URL shortner, which is awesome btw! You can easily track the number of clicks your shared link generated through the people who follow you.

However, today I checked immediately after I shared a link. It struck me that within 16 seconds the link already generated 7 clicks!

Twitbots

So I wonder how many of the clicks are generated by bots automatically click on these links. Anybody an idea?