I noticed that just writing a lens on Squidoo doesn't get me anywhere. How do I promote my lens? How do I make it a lens that is viewed and commented on by many people? I've seen others achieve results, but how do they do it?

I'm not familiar with Squidoo, but I wonder if it's like Triond, where there are widgets on the pages of your articles or items? If that's the case, did you submit the pages to those social bookmarking sites? Otherwise, I think linking to the lens from Craigslist would help, as long as it wasn't considered spamming by that community.

Also with Triond, you can "attach" your pages to your Adsense account.

It is just like Triond in many ways. Squidoo has in-built promotion features for your articles as well, so you can build a 'lens' (that's what they call their articles) and promote them to gain traffic. And you can make money through various advertising networks, including Google Adwords.

Triond and Squidoo are pretty much interchangeable. Whatever you're most comfortable with, I guess.

I believe that Triond wants content that isn't anywhere else online. I assume that Squidoo is looking for exclusive content as well?

I've seen some articles on Triond that I thought were pretty good.

Squidoo allows you to collate content, so it doesn't NEED to be original. However, without original content, your Squidoo lens will never be successful due to Google's duplicate content penalty.