The thing is we can create the profile backlink on Stumbleupon easily. But after that, what should we do next to have quality backlink? or just let the profile backlink there and wait for the returned backlink!
StumbleUpon is according to me, one of the very few websites which will help you to increase your traffic and provide you a backlink to your website as well. Although, you should not expect a lot of backlinks from StumbleUpon but it can help you get a lot of traffic. For this, you have to first register on StumbleUpon.