Ok, I read the admin/user guides, but I´m hoping to get live feedback. It seems installing phpadsnew in a subdomain would give me cleaner stats and avoid cookie problems. It looks like it would also be better to have it this way if I later upgrade the server (currently using shared hosting) to VPS or dedicated. What´s the downside or disadvantages if any?

most cases (especially in a shared environment) the subdomain points to a folder in the root directory anyway. So ads.yoursite.com also resolves to yoursite.com/ads

I'm not sure exactly how phpads handles urls. If memory servers me they do not have a settings that stores a particular url, but rather build one based on the incoming one.

So it makes no difference at all on a shared server? I read that if you use a subdirectory install, invoking locally, the ads will be cached by the browser; but, using subdomains (remote invocation) the ads will be called again from the web server. What I´m trying to do is weigh the advantages/disadvantages and keep phpadsnew stats from showing up in mydomain.com stats. So I guess that invoking remotely will use more bandwith. What I think I´ll do is probably install in a subdirectory and move everything to a subdomain later if I have to. I was just trying to avoid some hassle down the road.