Themed links, that is a link from the same theme or category as your own web site, is much more worthwhile than a link from an unrelated web site. For example, if you have a web site about shoes, a link from a web site about weight loss would not be as effective in increasing your link popularity as a link from another web site about shoes.

If you think of links as votes, it’s better to have a vote from within the same industry than a vote from another industry. Although it’s thought to be not completely worthless to have a link from an unrelated web site, it does less for your web site’s link popularity.

Themed links are important when you engage in link exchanges or when you buy text link ads. To get the maximum benefit from a link exchange or text link ad, it’s definitely better to look for web sites that are in the same themed as yours than unrelated sites.