Are most social boomarking site links indexed?

[ichthyous]

I have recently added a well known button to my site so that visitors can add my pages to various social bookmarking sites. Google's reported backlinks in WMT have updated twice since then and not one link is being reported back from any of the sites. The top choices have been MSN live, digg, and myspace...with various others trailing behind. Do any of these links get indexed and count as backlinks by google?

As an aside, I see in Yahoo site search that some of the links tend to produce mutliple backlinks as they are shared and move from page to page. Any risk of a sudden burst of links all at the same time causing a spam filter to be triggered? Thanks!

[Rosalind]

A lot of them are nofollowed, so success in social bookmarks doesn't necessarily lead to a search engine boost.

[martinibuster]

The idea is to gain links from people discovering your site through social bookmarking sites then linking to it from their blogs, directories, websites, etc. Same principle with stumbleupon.

[ichthyous]

Yes, I wasn't sure how many were nofollowed. The bottom line with this type of traffic is though...they look a lot and don't buy anything. It's not really useful traffic in any way, at least not for me. I did notice good seems to index stumbleupon profiles though. What about myspace and facebook bookmarks, are those nofollowed? Do they appear on users profile pages as links?