I guess its fairly common sense, I just wanted to make sure. the reason I ask is because I noticed a had a few nofollow links when I did a backlink check from a forum promotion board. why would they do that? makes no sense.
Why would sites do it? Because they already have plenty of traffic... and don't need any more! Even no-follow links have some value. Recently one of my comments at Hubspot blog (no follow) resulted in my getting an e-mail from a site's owner, asking me to join his new networking site (Do Follow). I got 5 new valuable links from this site, which I never would have found without the no-follow links at Hubspot.
If you want to know and get some free quality links read this thread http://forums.digitalpoint.com/showthread.php?t=1252071
Unlike nofollow, dofollow links are counted by google as backlinks. But both of them are important, for they can drive traffic to a site.
By defining the "nofollow", it will be easy to understand what a do follow is. "nofollow" is an HTML attribute value used to instruct some search engines that a hyperlink should not influence the link target's ranking in the search engine's index. It is intended to reduce the effectiveness of certain types of search engine spam, thereby improving the quality of search engine results and preventing spamdexing from occurring. The nofollow attribute value is not meant for blocking access to content, or for preventing content to be indexed by search engines. The proper methods for blocking search engine spiders to access content on a website or for preventing them to include the content of a page in their index are the Robots Exclusion Standard (robots.txt) for blocking access and on-page Meta Elements that are designed to specify on an individual page level what a search engine spider should or should not do with the content of the crawled page.