Jolly_Roger - 11:00 pm on Mar 9, 2007 (gmt 0)

EFV noted that:

When making comparisons of "this month last year" to "this month this year," you need to eliminate all other variables to get a meaningful result. That's hard to do unless: - Your content is exactly the same as it was last year. - Your traffic sources are exactly the same as they were last year. - Your ad placement, page layout, etc. are exactly the same as they were last year.

Funny, EFV, but you left out of the list the fact that a year is so long in Internet time that holding those three items constant is not nearly enough.

One would have to hold the advertisers and users knowledge and practices constant as well, among other things. But those standards may be a little strict for what we're doing here. ;)

No, we can't ever know for sure, even with your rules applied, but we can still struggle to try.