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.

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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).

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