One of the most common questions I get from webmasters and SEOs who are looking to build out city combinations because they have physical stores in those locations is how much unique content do I need on those pages.
The scenario is as follows... I sell X in the following cities and we have locations in each area. I want to optimize for selling X in city Y. The best bet is to have Google+ Local pages but also you want pages on your web site about each location. But how much unique content do you need on each of those pages?
Matt Cutts told Eric Enge of Stone Template in a really awesome interview with Cutts. Matt Cutts said, he'd think 2-3 sentences about what is unique about that location should be enough unique content for that page to rank.
Here is the quote from Eric's interview:
In addition to address and contact information, 2 or 3 sentences about what is unique to that location and they should be fine.
I strongly recommend you read the full interview with Cutts.
I pulled out another highlight last night, something that I found to be very unique and not spoken about until this interview and posted it on Search Engine Land. I titled it Cutts: Infographic Links Might Get Discounted In The Future.
Eric is one of the best interviewers in the SEO industry.
Image credit to BigStockPhoto for parrot