AdSense & Slimstat numbers not matching.

[NickCoons]

On one of my sites with AdSense, I use Slimstat for my visitor tracking to see number of visits, uniques, how they got there, etc. I've noticed a large gap between what it shows as the number of visitors that I have versus what AdSense shows.

I have AdSense ads on every page of this particular site, so my thought is that one visitor viewing one page would generate one page view in Slimstat and one page impression in AdSense. But that's not at all the case. Without giving away my exact page view statistics for September (I'll use a constant "X"), here's what I see:

Slimstat Impressions - 36X
Slimstat Visitors - 19X
AdSense Impressions - 8X

So I have 36 page views for every 19 visitors, which is fine. But I only have 8 page views logged in AdSense for every 36 visitors.

Slimstat has a feature that will allow you to not log search engine crawlers, which is enabled, so they don't skew the results. But I'm not sure how Slimstat does this (I haven't been able to find a list of search engines, user agents, or IP addresses in the software).

I'm wondering if anyone can provide insight as to why this disparity. I've considered the following possibilities:

- Most of the people visiting my site don't have JavaScript enabled, so AdSense ads aren't displayed.
- Most of the people visiting my site have ad-blocking software that blocks AdSense.
- Slimstat is not able to accurately detect all search engines crawling the site.

The last of those options seems to the most likely to me. And if that's the case, I'd like to know how the software does what it does so I can fix it to bring its numbers and the AdSense numbers more in sync.

[BigDave]

It is most likely spambots, not search engine bots that are the major difference. Unlike the search engine bots, they will try to mimic browser User Agents, so they are much harder to spot.

Trying to get log based stats to match up with your adsense stats is a waste of time. You will just stress yourself out.

[NickCoons]

It is most likely spambots, not search engine bots that are the major difference. Unlike the search engine bots, they will try to mimic browser User Agents, so they are much harder to spot.

Makes sense.. I get quite a few spam submission attempts (which my CAPTCHAs and double opt-ins block) into various forms on the site.

I have no idea how prevalent ad-blocking software is, and didn't want to think that a large majority of people visiting my site were using it.

Trying to get log based stats to match up with your adsense stats is a waste of time. You will just stress yourself out.

Sounds good. I'm glad I'm not the only one in this boat :-).

So what's the commonly-accepted method of tracking actual visits? Do people use their tracking software (like Slimstats), their AdSense impressions, or do the numbers not matter nearly as much as the trends?

[whizkiddo]

use urchin / sitemeter or slimstats as in your case. you will as u already have find a constant relationship between the two reports. That usually stays that way, for your own understanding I suggest you use your stats software and not google adsense impressions. if there is a major discrepancy something that is certainly not fitting into the 36X / 19X factors that u mentioned then its time to worry. but as someone pointed out, adsense impressions and the ones reported by our stats softwares are never the same. reasons and impressions vary from site to site. some of the most important ones having been mentioned above.