Bookmarking software - best thing about them - multi accounts or multiple site submissions

I am a bit confused about social bookmarking software.

Does their power come from being able to create multiple accounts on 1 site and helping your bookmark gain popularity to help it get on its own 2 feet so to speak?

or

Being able to submit to multiple sites?



Im curious because bookmarking a site on 10 of the most popular bookmarking sites takes about 10 minutes (once you have created the accounts).

But i fail to see how this is a good thing, i have been using stumbleupon and digg for some time, i always bookmark my articles along with random sites (i do actually use them because i like them, not just for SEO purposes) but nothing i ever submit ends up getting me any traffic because like millions of other submissions they just get buried because no one diggs them etc.

The real power from Bookmarking sites seems to come from building up followers and having a group of people who will naturally help you climb up the ranks on the site.

Once the ball start rolling it will take care of itself

I tried this myself just as a test to see, i submitted one article and get 15 people to bookmark my site (using microworkers) its bringing in a steady stream of visitors now because it has become slightly popular and i get about 5 referals per day!! Might not seem a lot but i have never got any referals in the past.


So where does the real power come from in using these bookmarking products?