After about five minutes I moved out of the top 100; I opened another page and there I was, back at number 1, and showing total page views equal to one.

That is what the Ruffini Hypothesis would have predicted; here is what mark said:

So yes, if I let myself fall off the page and refresh, I’ll appear in the list again, but that does not mean that SiteMeter is counting me as a new unique visit.

Let’s see – it shows me on the visitor page with a new timestamp and one page view, after spending five minutes correctly counting me as a one-time visitor opening multiple pages.

OK – that does not *prove* that Sitemeter is not handling it correctly, since maybe all their stats are based on calculations to which we lack access. Of course, that amounts to a faith-based initiative that Sitemeter is doing it right.

But what they are doing that we can see is certainly consistent with the notion that after 100 visitors you are new again regardless of elapsed time. At Kos, in prime time, folks are new after ten-fifteen seconds; at my site, it takes five minutes.

More data – back at my test low-traffic site, I am now appearing twice on the main page as a unique visitor. I arrived at 4:43, did my next-to-last page-open at about 5:10, and just opened another page at 5:48.

As predicted by Sitemeter fans, since a half-hour had elapsed since my last page-open, I am unique again.

I think I am understanding this.

First of all, feel free to try this yourself – opening three pages and hitting refresh twenty seconds apart can be done in less than a minute. The copy/paste/sort is not exactly technological high frontier, either.

Secondly, more than half the details provided by Sitemeter are a generic “Comcast”, Optonline”, or whatever, and I dropped those. Among 118 that presented a specific IP address, I got the twelve duplicates noted.

From Mark:

I do know my IP address, and was able to track myself. It appears to display the last 100 unique IP addresses that accessed the site, sorted by the timestamp of their most recent page view (in descending order).

Really? I went to a very low traffic site and my timestamp has not changed even though I clicked on a total of five pages over a span of twenty seven minutes. And two folks appeared after I did, but but place on the list remained based on my *first* appearance, not my final refresh.

Interestingly, I have now been there a total of thirty-three minutes but it still thinks I am one unique visitor; an obvious explanation is that Sitemeter is also tracking my “Last refresh” (as well as first visit) and will not think of me as new again until at half hour elapses from my last refresh.

More details – Sitemeter is keeping a correct count of the pages I have visited at the low traffic site, but is holding my place based on the first entry timestamp, as noted.

So, to test Mark’s notion, one might wonder – if you drop off the Hot 100 Sitemeter page and then open a new page at the test site do you (a) show up as a new visitor with a page view count of 1, or (b) show up as a new visitor with a page count of 2?

I have switched computers yet again but I am pretty sure that the duplicate visitors in my Kos test were scored as hitting their first page, even though the time lag was about twenty seconds.

If Sitemeter does not have the “Last 100″ hidden constraint described by Mr. Ruffini, then the three lists should contain *zero* duplicates for IP addresses.

You’re assuming that if a person moves up on the list, they’ve been counted as a new unique visit. I do know my IP address, and was able to track myself. It appears to display the last 100 unique IP addresses that accessed the site, sorted by the timestamp of their most recent page view (in descending order). So yes, if I let myself fall off the page and refresh, I’ll appear in the list again, but that does not mean that SiteMeter is counting me as a new unique visit.

During the day, Kos is getting about 30,000 visits per hour, or 100 each 12 seconds.

so – open three copies of the Kos detail page, each listing 100 visitors.

Refresh them roughly twenty seconds apart.

If Sitemeter does not have the “Last 100” hidden constraint described by Mr. Ruffini, then the three lists should contain *zero* duplicates for IP addresses.

But if Sitemeter does have the hidden constraint, then folks who click a second page after twelve seconds will appear twice.

I did a cursory try (copying everything into Excel and sorting) and got twelve duplicate IP addresses among 118 ostensibly unique visitors over about a one minute span. And yes, the identical visits ocurred more than twelve seconds apart. For example, one IP was visitor 15 on one page and visitor 2 on another.

So my money is firmly on Patrick here.

When is somebody going to ask Den Beste how this shit really works?

Can’t we just take their FAQ at face value and accept that visits time out after 30 minutes?

By far the most likely reason you don’t see extra visitor info immediately upon upgrading is that SiteMeter simply does not store personal info past 100 visitors for basic accounts.

That may be true (that visitor “details” are only stored for display purposes). But they don’t need to store “details” to track visitors accurately. They need an IP and a timestamp. That’s it. I left more info in a comment on your site, Patrick.