"No ads" is a good alternative, because the extra spreadability you get is worth far more than the pennies you'll be able to extract from advertising at an audience of tens or hundreds.<p>The other alternative -- and again, "no ads" is better, is to put up your add blocks, seed with one ad for a related affiliate offer or even an ad-looking block towards a page in the space, and then have the other blocks say "Click here to buy this space." You can then do the simplest possible thing to enable that -- e.g. email me and I'll take your payment by Paypal.
Last I checked, and this was 6 months ago, there isn't really a comparable ad service to AdSense in terms of quality. Nothing else I've seen manages to serve such targeted, high quality ads.<p>That said, you can make good money from other approaches like affiliate marketing, products, and so on.