I never claimed nofollow was some sort of panacea. nofollow makes spam less profitable, period.

Hashcash users cannot reject an unstamped (or invalidly stamped) message outright. When everybody uses it and software becomes better trusted and debugged, they will; but until then the only reasonable way to use it is with a scoring filter, and never set the scores high enough that the binary decision about a message is made solely by its hashcash status. "Make no mistake, we're talking about a pretty large time scale here."

I also never claimed comment spam was useful solely because it influences rankings. (I don't know why you insist to think that I did.) Spammers will spam where they expect return on their investment. Period. What I do claim is that comment spam's ability to influence rankings — and especially to "hijack" the top hits in large search engines — is an entirely new class of opportunity for spammers, which gave them hella lot of incentive to start doing it. Of course there's inertia, and of course they won't stop just because you take some of the profit away. If suddenly litigation rises a hundredfold, spam won't stop either. But all other things being equal, I believe that it will slow down.

There is no contradiction in what I wrote. The individual blogger does not benefit from nofollow. I don't want to read spam; not even to delete it from the moderation queue. The less of my time spammers can occupy, the better. I don't even want to know that a spammer is trying to dump a pile on my web log until I check the logs of deflected spam attempts.

The fact that nofollow enables highschool antics and popularity contests is beside the point. It is not a benefit.

Hashcash in email is problematic and a long-term undertaking indeed, but I'm talking about hashcash on web logs where it is 100% reliable. It does present problems for those with Javascript disabled, but that's a different class of problem.

Yes, spamming comments to influence search engine results is a distinct class of revenue generator indeed — and one that's here to stay: there are millions of unattended blogs which are going nowhere and will not be implementing nofollow anytime soon.

Makeshifts last the longest.

Guess what? I don't want spam to exist either. I thought that's why we were looking for ways to lessen it; I don't quite see how your frustration at spam figures as part of your argument against nofollow. That it does not provide you with immediate satisfaction is unfortunate, but hardly proof of its worthlessness. Would you reject antibiotic treatment for an ear infection just because it isn't instantaneous? If you were a doctor, would you not prescribe liniment for a patient with chronic arthritis because it isn't a complete cure?

I didn't realize you were talking about hashcash in weblogs. Why do you think it is 100% reliable there and not in email? What makes you think Javascript is not an imminent part of the deployment problem?

One of the first attempts at implementations of hashcash for weblogs is just broken. That is, the person who made it didn't understand what hashcash is at all; the whole point is that stamps are somewhat expensive to create. Basically, they just have a challenge-response system with no crypto at all, which is only a little more difficult for the spammer to overcome than learning a new blog post format.

Granted, a solution that does implement hashcash can spring up any time now. Good, let it. Then you have to deal with the Javascript problem. Which is quite similar to the deployment problem of hashcash on other platforms such as email. Or, of course, you could reject clients that don't play along, but you know, you could also charge them $50 a comment and be done with it.

Those unattended blogs, they won't be implementing hashcash, either, but I guess that's not your problem.