Unique IP == Unique Visitor?

Hi, i am gonna code a Ad program, but i really need to clarify myself before going too far.

Can we consider unique ip as unique visitor? I am sure that there are only 256x256x256x256 ips in the world. And i even heard bout some area sharing the same ip, am i correct?

plz clarify me if i am wrong


How those wellknown yahoo, google consider a unique visitor click?

 

Unique visitor does not mean unique IP.Two ppl who shares same computer are also unique visitors but not unique IPs.It is better to mention unique IPs instead of visitors

 

ya, but we should consider in major issue, rite?
Anyway thanks for your idea

 

Well .. For example - I have 2 user accounts in my computer .. Logged from User 1, i visit the site, and it counts ar unique visit .. i log into second account, and visit the same site - this is already second unique visit from my one ip

 

Yea, if we consider the case as two impressions but not one, i am sure the Advertiser will get mad

 

you should be using cookies rather than counting through ip address. also, you have to keep track of the ip address (maybe through the logs) and make sure there isn't suspicious activity (similar trends) from the same ip address