I tried, I just wasted a few minutes clicking "Random Page" and ALL results are about the supermemo software itself, most are support emails republished as wiki pages.
like the other guy said "wide range of topics". If you click random you just go to short article after short article about the app?
Click one of the articles from the front page. The short articles about the app are because the wiki is also used to answer questions from users of the app.