Just had an unusual problem I thought I'd share for those running both AdSense and AdWords.

I used to run an AdWords campaign that has been idle for months.

Suddenly the landing page for that campaign started having completely off the wall ads, not even close to the content.

Turns out the only bot crawling that page was the AdsBot-Google for AdWords and it was being blocked.

Normally you only think about googlebot and mediapartners-google crawling and sharing cache pages for AdSense as they are the two main 'bots crawling your site.

However, I had completely forgotten about the old AdWords campaign and AdsBot-Google was definitely not authorized to crawl my site.

Allowing AdsBot-Google completely cleared up the problem.

So just a heads up for anyone running AdWords and AdSense, please make sure you allow AdsBot-Google on your site as well JUST IN CASE!