Blog Traffic

All of a sudden I have no idea how many people visit this blog — or anyone else’s blog for that matter.
N.Z. Bear writes at Tech Central Station:

[I]t should also be noted that not everyone in the weblog world believes that SiteMeter data are perfect, or even the best counter available. Some bloggers scoff at SiteMeter, claiming that the results it provides undercount the actual traffic they see by measuring traffic more directly from their server logs. These complaints may or may not be true: I frankly don’t know.

This is news to me. I’ve used SiteMeter ever since I started this blog and always assumed it was reasonably accurate. Maybe it’s not.
So I checked my traffic level using Webalizer (which is installed on my server), something I’ve never done before. And I was shocked.
SiteMeter says the average number of visits per day on my blog is 3,200.
Webalizer says my daily average is almost 6,000 for the same time period.
What’s the deal? How can these two traffic counters be off by so much? Does anyone have an informed opinion? (Both SiteMeter and Webalizer claim to count a single visit as all activity on my Web site from a single IP address with less than 30 minutes of idle time in a row between clicks. So it’s not like they’re comparing apples and oranges.)
I’m slightly inclined to believe the Webalizer stats since Webalizer is actually installed on my server and SiteMeter isn’t. But maybe there’s a flaw in the code that leads to overcounting. I’ve no idea.
I really would like to know how many people stop by here every day. It’s not just about ego or idle curiosity.
As N.Z. Bear notes at TCS:

This is a real problem, and one that will only grow in importance as weblogs continue to take their place alongside traditional media as a source of information and entertainment. Blogging is no longer exclusively a hobby done for the sheer pleasure of it: for some, it’s a business, with real money coming in from real advertisers — who want to know exactly what real traffic they’re paying for.

Yep. Maybe someone should conduct an experiment. Create a place-holder Web site where you can control exactly how much traffic it gets because you’ll be the only one visiting. Keep a careful tally of how many “visits” you auto-generate. Then compare different traffic counters and see which ones are accurate and which ones are not.
It would be a pain, but also a real public service.