Any one get any success with a campaign with Stumble? reason i ask is because i just setup a quick campaign and deposited $5 and the $5 was gone within 3 mins. Seems a little to quick to send 100 people.
They do have over 1,000,000 members I believe that is stumbling their site. If the thing that you were promoting was not entertaining, then it would have not really done well.
I have tried them and it didn't really deliver the results I was looking for. I am told that it works better with larger campaigns ie. $100. But remember there are certain websites that are successful on SU and not all sites are appreciated by the community
I have tried their advertising package in the past and I have compared the result with organic stumbling and the result is, less users from paid stumbleupon thumbs up my page. I get better result from just free stumbles. Check this post.
As cherry said, you can get a much better unique visitors from free stumbles and promoting your website, adding friends, networking on SU.. and so forth. Check out the Freebies forum - tonnes of people do Stumble Exchanges to drive traffic to their websites, including myself!