- Website/URL - First, you will need to see if the blog's comment form allows you to enter your URL. Some sites either do not have this option, make you register for their site, have you login through Facebook, Disqus, or other means where the link to your name in the comments will only take someone to a profile on other sites, as opposed to the URL you are trying to build backlinks.
- DoFollow - Most blogs specifically have a "nofollow" attribute on the URL, which means that although your named will be linked to the URL you enter, it will not be "seen" by search engines, and therefore will do no good in terms of linkbuilding. What you are looking for are sites that offer DoFollow links. One way to find DoFollow blogs is to search the Do Follow Blogs and Do Follow Blog List directories.
- Keyword Luv - Some blogs with dofollow have a specific option that allows you to enter Your Name @ Your Keywords. This way, you are able to use specific anchor text, such as Jeff @ Spa Covers, for your links, boosting the keyword value. Although you can just put your name as Spa Covers, some sites (usually ones with a specific comment policy) frown upon this and may not approve your comment, flagging it as spam.
- Relevant Comments - Speaking of spam, another way to look like a spammer is to place irrelevant comments on articles, or comments that are so vague that they could apply to any article. Be sure to at least skim over the article and write a valuable comment, aside from "wow, what a great post" kind of comment.
One way to tell is to use the Firefox plugin NoDoFollow. Once installed, you can simply right click on a blog article with comments and select NoDoFollow. If the commenters' links are highlighted with purple for dofollow, then the links will be recognized by search engines.
