"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.
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.
Depending on your end goal, I completely disagree.
If you are putting up a company blog, sure no ads is fine. But if your ultimate plan is to have ads on the site, add them early. You don't want to spring them on people once you gain traction. There will be backlash.
Your premise behind no-ads seems to be that somehow people are more willing to share or visit a site with no ads. I don't think that's the case at all (within reason).
Also, selling your own ads tends to be a waste of time at small scale, unless you have very specialized and lucrative market.
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.
That said, you can make good money from other approaches like affiliate marketing, products, and so on.
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.