Hey! I read some posts about how bad is the stumbleupon traffic but in my site: Hot photoshop tutorials the people who come from stumbleupon stay about 2 minute and targeted traffic (in my case- good-tutorials traffic) stay for 1 minute... I don't realy know what is the reason for that... maybe the design, maybe the content.. :S but anyways- I think any traffic is good except PPP site's traffic or something like this. what do you think?
SU is good to let people know about your site. yes, most of them are low quality visitors but you can expect few quality visitors. Who know those "few" people will give you natural back links, etc.?
nowadays, natural back links are very hard to get... even if you're content is good. ofcource, there are always some big sites that have a lot of natural back links..
SU Traffic for me was next to useless.. I did get 2 SU backlinks, but other than that, a big waste of bandwith.
Hahaha. When my site, www.affiliateunleashed.com got stumbled upon, I got something like 200ish unique visitors from it. Opt-in rate was 10 times less than normal visitors. That's quality... :S If it were a different niche, I think it might be better conversions.