High Amount of Backlinks on About.com

Guys,
About.com has forums for pretty much any niche and they allow you to add your signature and homepage url right when you sign up. The first post i made had my signature with my keyword as my anchor text and the link to my site. Is there anything wrong with this because it seems like getting backlinks is easy now as long as you make a few posts per day? Are these do-follow links or are they even worth getting?

nice to hear this... about.com is getting in the way to the #1 for some keywords...

Im interested to know if its worth registering and making links in signatures etc as well

Check if these links are do-follow