Tumblr and Squidoo for S.E.O.?

Are Tumblr and Squidoo effective in creatiing backlinks for SEO? I'm using them right now but before I continue spending large amounts of time there, I'd like to know if my efforts will come to fruition?

 

yes, and now only that, you will also get some good traffic from that as well

 

Yes, both those sites are worth creating sites on and linking back to your money site.

 

It depends on the theme of your sites and keywords you choose for lenses. Some of my efforts got wasted with general keywords. I also would not spend to much time there alone - there's plenty similar web properties recently created where you don't have as much competition in your themes.
In my opinion the link from those sites is more important than the traffic you can expect.

 

my experience is that squidoo is great for backlinks, i have never had much success with tumblr though

 

Both are good enough to get backlinks and traffic!