How does a webmaster know if someone has only been to his/her site once as compared to multiple times ?
*just because someone types in a URL, does not mean they have been there before. Allot of us have had articles posted in papers, local TV news and so on about us which require people to type in the URL.
Here are a couple of examples done about my site
http://216.158.136.80/news.asf (1998)
http://www.lasvegasweekly.com/featur..._you_mine.html (1999)
*Just because a surfer finds his way to a site does not mean it came from an affiliate link, so saying first time = affilaite link is not accurate.
Actually knowing the info your asking about is almost impossible, for someone who thinks you only have to track IP address then have a program compare them, dial-up accounts and proxy servers make that impossible.