Be Creative and Visible
One of our most successful methods for increasing link popularity is to offer "awards" (a gif that links back to our site). We create a strong incentive for the awardee to place the award on their site because the awardee perceives a benefit - he gets to tell the world that another site recognized his site as a quality site. One way we do this at SEO OFFICE is to offer "Star Performer" awards to Web sites that get 4 or more stars on their site when they run our validator tool over their site. This tells people visiting the awardee's site, that the award-winning site is a professional site run by individuals interested in quality assurance and providing a good visitor experience. Remember to make it easy for awardees to place the award gif on their site. Have the snippet of code available so all they have to do is cut and paste it into their Web page. Even if your site doesn't support an award, offer visitors a gif to put on their site. You'd be surprised how many people are willing to do something like this for a site they like.
Build a stand alone search engine or directory. Add your own sites, your clients' sites, your affiliate sites, your own sites that are affiliates for others, etc. It's a great way to legitimately build link popularity for all your sites, even if they are unrelated. Some programs will even allow you to supplement your results with ODP. You can find search engine and directory programs at The CGI Resource Index (http://cgi.resourceindex.com/Programs_and_Scripts/Perl/Link_
Indexing_Scripts/) and The PHP Resource Index (http://php.resourceindex.com/Complete_Scripts/Link_Management
/Directories and_Portals/). You can also build a stand-alone themed search engine or directory, with a link to your own site.
If someone wants to interview you for an article in your related field, say YES immediately! That person will list your qualifications with a link back to your site as part of your introduction. Plus, you'll get added visibility and credibility for your Web site and online business.
Although joining a banner exchange program would probably not improve your link popularity, you can improve your link popularity by starting your own banner exchange service. The concept of these services is that people sign up and agree to add special links to your Web site. Your server will then display banner ads on their pages. In exchange, you agree to automatically display a certain number of their banners on your own site and other Web sites within your banner exchange network.