Creating a counter

For a basic counter, store the IP address of last visitor wherever your store the count. Then compare the current IP with the last known. This work fairly well on sites not visited much. However, if two people are actively browsing pages that all use the same counter, as their hits alternate back and forth they will increase each time the other person was the last one to visit a page.

Off the top of my head, (I use counter/stat services, never wrote my own), I would say if you have a database, store each IP with the last timestamp. Then each visit check to see if the IP is in the list of all IP's. You would need something that clears the list once it gets so old, like run an hourly cron job that deletes any entries that are more than like 2 hours old.

Tracking how long someone has visited a page only works as long as they are staying on your site. I'm trying to think of the stats program I used once that tracked this. If I can find it, I'll post it here.

-Greg

for checking how long they stay at your site you have to use sessions or cookies, on a page you can't really get a true picture until they move to another page, but can get tricky as you first have to check they did come from another page on your site