Grabbing IP address

Jon12345

Can you always grab the ip address from your visitor using $ipaddress=$_SERVER['REMOTE_ADDR']; or are there circumstances where the surfer's address cannot be seen?

Thanks,

Jon

Piranha

Routers, proxys is cases that I can think of when you can't see the true IP address.

MarkR

You will always get AN address for the client. This is the address which the server is communicating with, which is usually "good enough".

The server might not be communicating directly with the client however, as there may be proxy server (s) and/or NAT happening.

Either way, $_SERVER['REMOTE_ADDR'] gives you what you want.

Mark

Jon12345

I am asking this because my sales statistics are 2/3rds or what they should be. When someone gets to my webpage, I log their ip address. When they get to the merchants sales completion page, a single pixel gif accesses a page on my site which searches for an existing ip address. If it exists, it places a sale in the database. If not, nothing happens.

So, could something I am doing here be causing my sales to appear lower than they are? Any ideas?

banzaimonkey

There could be a variety of things happening.

On the technical side of things, if someone has adblocking software and they're blocking that particular part of your site, the GIF would not be downloaded. If they've already viewed the page and the image is cached, then it won't download the next time. If they don't view the confirmation page or don't allow it to fully load, the image may not be displayed. And of course, there could be an error with the GIF tracking code.

Google Analytics, and many other web analytics services are now paying a great deal of attention to a process called "funneling", which is designed to address the issue you raised. Essentially, funneling is designed to track a user's progress through a sale, from start to end point, and highlight any areas in which the user may fall out of that process, whether it's because of technical problems, difficulty in navigation, or loss of interest. Using a similar technique may be a good way to find out what's happening.

I'm curious as to why you don't update the sales record using the PHP script in the first place, rather than using a GIF. It seems like it would be a much more straight-forward method.

Jon12345

I do update it using php, but via a remote gif. But I don't have control of the sales confirmation page so cannot add code to it except a single pixel gif link. That is all I am allowed.

banzaimonkey

Ah, I see. That's a bit inconvenient.

If the image is remotely hosted, various browser may block the image. Remote images are sometimes blocked for security, because they're usually tracking images. I don't know how prevalently remote images are blocked, though; I wouldn't expect enough to account for 1/3 of your stats missing.

I've heard that ISPs such as AOL use forced-anonymous proxies to connect people to the internet. I don't know how frequently that cycles, but if there's a significant amount of time between the hit on your site and the hit on the merchant page (and proxy information changes between those) then the IP address could be different.

There could also be something happening on shared connections, with multiple users accessing the pages from the same IP, etc. Some of these things you could probably find out by analyzing your stats, but it'd be a bit tricky.

I could dream up lots of nasty scenarios eating your stats. I think the bottom line, though, is that no web stats (or any stats, really) are going to be 100% accurate. You just have to design your metrics in such a way that they'll work even if they aren't accurate all the time, for whatever reason; dropped packets, rebellious pixels, etc.