Since I started using Squidoo primarily as a source of one way links, most being deep links to sites I own, promoting the lenses themselves cant be done back on the conventional websites that I own.
As you implied, this leaves social networks as the main tools for adding backlinks and sending traffic to lenses.
When I look for social networks, i want a simple interface, the ability to add dofollow links and hopefully some human traffic.
I use facebook, myspace, gather, etc.
If I had a lens where income was critical, i would not hesitate to use conventional methods of promotion such as article submissions, press releases, directory submissions, etc.
Wow, first let me say this is just odd. Daybreak was a 'handle' I used way back in the bulletin board days.. my first social networking experience involved a chat room that could handle 6-8 people called Sophia.. and they were thrilled that I was a female participating. My how far we have come wouldn't you say.
While I'm not new to the net, I am new to the web design world. It is an amazing process and Squidoo is already a huge favorite of mine. I love that everyone can participate.
I am actively working on promoting my lenses and finding that aspect more challenging. There is so much to learn and finding out what really works still has yet to unfold itself to me. I am pretty much following the recommended links/networks found in many helpful lenses and trying to weed through the net information. Probably my all time favorite for pulling it all in is MyBlogLog and going from there.
Probably the biggest single thing that has helped me increase traffic was to learn how to check my stats and find what tags and keywords were bringing traffic to the lens. I use the + option in the stats to add good tags to the lens, remove ineffecient tags if I have too many, then republish it.
I've got my hands in so many pies, it takes as much as two weeks to do all of the promoting one lens needs just to get started. My first go-to sites are Facebook, Delicious, Magnolia, MySpace, and Digg. I also Tweet my lenses from time to time, and I'm a member of several Ning networks and other forums that focus on some of the same topics as my best lenses.
I will usually stop lens production for a week or so once I've published something new, and surf all of my favorite forums - including SquidU. I don't always post my own work, but I try to answer questions and interact with other members. I've tried other Squidoo forums like Squidom, but I didn't get very good results from them.