Fighting against repetitive clicks

I'm writing an Adsense style adserver now. Want to know 开发者_如何学编程which are the best methods to fight against repetitive clicks. Now i'm storing the clickers IP address in an other table, and allow 1 click in every 24hr for an ad. This solution is not the best, and it still can be screwed. How does Google and the others does?

Thanks for the suggestions.

One click per 24h will hurt your business big time. Just think of big organizations with just one public IP for their "staff computers".

As far as I know, there is no proper solution to this, but a combination of these things might do the trick for you:

1. Check in your session if a click has already occurred.
2. Check against a cookie.
3. If using flash, check against a shared object.
4. IP-based limit (but probably much more lax than what you've got now).

Also up-voted Michael J.V's comment. Collecting data about the specific client (and store in database) will make much sense.

Of course, people can spoof that data, but I don't think you can do anything about that (except having a lax IP-based limit).

My solution: Store a cookie + an IP etc. Maybe even sessions are helpful.