Advert Click Validation

I am working on a sensible advert exchange system.

Most of the ones out there have crappy interfaces over crappy codes.

I want to do somthing different.

What are the things I need to consider when validating clicks and impressions to ensure the integr开发者_StackOverflowity of the system.

Thanks in advance. :)

2. Define what constitutes a valid click.
3. Define what constitutes a valid impression.
4. Ensure that your code can determine which actions pass these definitions and which don't.