I have a client who offers a service. He ranks really well for some very competitive terms - consistently on the first page. However, in the past 3 months, the core terms that he used to be on page one for have dropped off the map and I have no idea why!
Here's what I mean... if the core search terms were "carpet cleaners" and "carpet cleaning"
He ranks highly for "mytown carpet cleaners" or "carpet cleaning mytown".
I can't see it being an issue with over-optimisation on-site as the other ones with the same terms rank well. It's definitely not over optimisation of incoming links either as we have done very little link building. It's mainly about content. Any ideas???