I submit to digg, propeller, diggo, mixx, a1, and folkd and the only links shown (webmaster tools) back to my bookmarked pages are digg and propeller. Just curious which social bookmarking sites you guys have used that actually give you links.
You already have digg and propeller. I liked furl but they were acquired. You can also likes of kirsty or dropjack.
Some social bookmarking sites sending me links are squidoo.com, connotea.org, jumptags.com, reddit.com, and simpy.com.
dropjack is no-follow. useless for link building. Maybe for traffic. I don't know about traffic, but Sphinn is using redirect to link to other websites bookmarked. You can see here what are the do-follow social bookmarking sites. Sure, there are more then listed, but those are the main ones. Once you use them, voila ! You got a usefull backlink.