Back in late summer I reevaluated the linking strategy between my websites. Up until then I'd used my main site to feed link juice into my newer sites - softwarelode and so on. I decided this was a bad thing to keep on doing, since my original intention was to feed link juice back into my main money-earning site and not do things the other way around.
It was interesting though to see how well sites like softwarelode responded to getting a few links from my main site. Basically within 3 weeks softwarelode started getting a few hundred visitors a day even though it was a new site. Predictably, when I removed the links the visitor numbers began to fall but at a much slower pace than the visitor numbers grew in the first place. Rather than the 3 weeks or so for the visitor numbers to peak, it took 2 to 3 months for the visitor numbers to fall away. During those 3 months, Google did some mini toolbar PageRank exports and some of the inner pages of softwarelode started showing PRs of 2 or 3. By early December though all pages apart from the homepage were showing PR N/A and visitor numbers were 20% of the peak.
As the visitors fell away, more of the softwarelode pages were falling into Google's supplemental index. When a page is in the supplemental index it's not going to turn up in SERPS execept for very specific/ obscure search phrases. The supplemental index is purgatory for web pages. I had a look around the web to see what advice I could find. As to be expected the advice was that old chestnut - build backlinks. So, before Christmas I did a spurt of backlink building and I'm pleased to say that since the New Year visitors are returning to softwarelode and the Adsense income is beginning to climb again. Since yesterday (5th Jan), an extra 350 pages are marked as being in the main index. I know of similar sites to softwarelode with about 2500 pages in the main index that make a decent amount of Adsense income (few hundred dollars a month) so hopefully I'm on target to making softwarelode an earning website by the middle of 2009.