You mean (1) more page views per unique visitor or (2) that server stats show a drop while G shows an increase?

1 maybe you have done something to encourage visitors stay on the site longer.
2 maybe you have done something to make pages download quicker so that visitors don't move on before the ads display.

Lots of other possibilities of course.

Sounds like a USR (Unidentified Software Robot) to me.

I really haven't done anything to cause this increase in Pageviews - it is #2 (slightly less traffic but substantially more pageviews reported by Adsense). I will try to find the USR then..

Do you have any hotlinked images?

This caused me huge problems last month from so-called sites offering services to gaming sites and myspace users by hotlinking through Google images and still referencing the actual url thereby generating page images.

Google Analytics does not pick up on this therefore my traffic for November had a huge increase with absolutely no extra earnings.

I suppose it can depend on how many pages 5% represents.

If 5% is a few hundred or maybe even a few thousand pages, it could be just a shift in the source of traffic.

For example, visitors from search engine A might visit more pages per visit than visitors from search engine B. So if you get a spike in traffic from search engine A that could be the answer.

Or you might have gotten a link from an active forum or such, those can generate a lot of traffic sometimes.

If it continues for a week or more that's one thing, if it drops off rapidly in the next few days, that's another.

5% means around 1400 pageviews and earnings were up too for Monday and Tuesday. Adsense numbers are back to normal for Wednesday although traffic was up around 1500 pageviews. I really can't explain this but I sure was hoping it would last, especially that the number of pageviews reported by Adsense is always lower than my server stats.