Unique Visitors = 1/10th of Unique IPs?

Max Fomitchev submitted a little blog entry where he proposes that the ratio of unique IPs to actual unique users is 10:1. This flies in the face of the numbers you usually see attached to these sorts of things. I'm not sure about the logic he uses to come up with these numbers either.

Comments

10 was arbitrary

[op12]

The 10 was a hypothetical...the only point was that you can't trust the number of recurring visitors that a site reports because they users come back with a different IP (obvious) and get counted twice. Couldn't one use cookies and IPs in combination to get a better gauge? The IP may change but the cookie would not. Sure some may delete it, but it'll still improve accuracy at least a little bit.

WTF?

[giorgiofr]

This argument is flawed. Logging to Slashdot now from my house and two hours from now from my friend's house should count for two visits, and so it rightfully does. The article writer seemed to have a problem with this? ZOMG 2 different IPs...
And if my IP has changed but I'm still here... that's because I haven't surfed for many hours at least otherwise the lease will be renewed and the address will stay the same. So it should still count for two visits. Duh.

I thought it was the opposite.

[Black Perl]

First of all, a DHCP server is typically going to give you the same IP address each time your computer requests it, unless there are more users than IP addresses, in which case there will be some shuffling. But that tends to be when there are more users than available IPs.

There are entire domains hidden behind a NAT device of some sort. This would be many users per IP address. TFA didn't mention this at all.

So I think TFA is indeed arbitrary, and also wrong.

Re:I thought it was the opposite.

[the melon]

Yeah, here at Sun there are nearly 40 thousand people that connect through 40-50 different proxy servers. That is a thousand to 1 in the opposite direction the article claims.

And yes, he seems to have no idea how DHCP really works. Even if your lease is expired you will get the same IP address unless the pool has been exausted and your address re-used. I see that as an extremly unlikely thing to happen because it would mean, as you say, that your pool is smaller than your installed base. If you pool is smaller then you will start having issues because x number of customers will always be without a connection because they can't get an address.

Had he mentioned Dialup users then I would be more inclined to agree because you are very likely to get a different address every time you connect.

My own stats say very different things.

[CFD339]

I did a quick analysis of a 250,000 line entry server log. I counted unique ip addresses, unique useragent cgi values, and then the number of unique combinations.

A useragent value looks like this: Mozilla/4.0 (compatible; MSIE 6.0; Windows 98; .NET CLR 1.1.4322)

Although even this is hardly reliable since useragent can be faked, and useragent isn't unique enough to be a client fingerprint -- its still helpful in this context.

One can make the assumption that a given user's "useragent" value isn't going to to change much on a day to day basis, though it will not stay the same over time as vesions get updated. GENERALLY speaking, the same IP address but different USERAGENT values would indicate different people from behind the same NAT firewall, or different users assigned the same DHCP address.

Here's what I got for results -- it looked like counting only unique IP's gave you only about 85% of the unique hits.

Total Hits Looked At: 249861
Unique IPs: 10309
Unique UAs: 1578
Unique Combos: 12232