

Designing For Evil - prakash
http://www.codinghorror.com/blog/archives/001123.html

======
stcredzero
This and TipJoy have inspired me. What about making a social news site, a
Wikipedia-like site, or a classified ads site where you can read and search
all you want for free, but you have to make a micropayment to post?
Micropayments would be in "credits" that cost 4.5 cents each. $5 gets you 100
credits. (There's a 50 cent processing fee.) You could also write the Terms of
Service such that spamming forfeits your $5.

You could even combine this with a TipJoy-like idea and have commenters tipped
for every up-vote. (Down-votes would subtract from a comment score, but not
affect the tip.)

This would kill off the spammers. Paying $5 per spam post would ruin their
business model. I suspect that it would also increase the quality of the posts
if posters could earn money from their efforts.

~~~
dfranke
specifically, your plan fails to account for

(*) extreme profitability of spam

Spammers would probably be willing to pay more to make each post than
legitimate users would.

~~~
hugh
I disagree. Spam has a low success rate, so it's only extremely profitable
when the cost per advertisement is zero. If you have a service where it costs
_any_ money to post then spammers will go find somewhere else.

I think it could work well for classified ads since that's something people
are willing to pay for. Not so well for wikipedia or social news, because who
cares enough to pay money for those?

I'd price classified ads at one dollar each -- small enough that it's
practically free, but large enough that you could easily make a lot of money
out of it if people ever decide to abandon craigslist.

------
michael_dorfman
That's a great piece-- Atwood at his best.

The lesson that "When good is dumb, evil will always triumph" is a simple one,
but surprisingly hard to put in practice.

------
mojuba
I think sites that run some kind of an automatic ranking or otherwise a user-
driven voting system are better protected from spam. To make it even better
there should the second level with weighted users (user ranking in other
words) to compensate massive automatic registrations of fake users.

I'm sure it is much easier for Flickr, for instance, to fight spam than for
Cragislist, because Flickr has an excellent automatic ranking system of photos
based on users' (implicit) votes plus users' weights. This at least prevents
spam from slipping into the daily top-500, and the rest is not that important.
They host all kinds of garbage anyway and that doesn't bother the community.

This is what makes spammers turn away from Flickr, I think. I have never seen
any spam on Flickr's top-500 page (well, except those crappy images with
anything-Apple insanely upvoted by a bunch of Apple fans).

------
come
This piece is pretty similar to this
[http://blogs.concedere.net:8080/blog/discipline/web/?permali...](http://blogs.concedere.net:8080/blog/discipline/web/?permalink=Those-
Who-Live-by-the-Spam.html)

------
cousin_it
Am I the only one wondering, why wouldn't Craigslist use a bayesian filter?
Plus posting delay so they can't retry quickly.

~~~
dreish
The problems I see with a Bayesian classifier in this application are:

1\. Spammers get instant feedback on whether their post was flagged. When they
send me email spam, for example, they have no idea how badly they're doing.

2\. Spammers have access to a large ham database to draw from -- all the posts
that were not filtered. With email, they never see any user's highly
individualized ham database.

3\. Bayesian classifiers require a significant amount of manual intervention,
especially given 1 and 2. I'm happy to correct classification errors in my
email when they happen at a rate of roughly 1/200,000, but if I had to stay on
top of dozens of false negatives and false positives every day, I just
wouldn't. Very quickly the database would become too noisy to be of much use.

