tedster - 11:24 pm on Jul 1, 2010 (gmt 0)
If we allow these listings to be indexed then google leaves lots of our city pages which are more important and indexes these listings. The same situations being discussed here [youtube.com...]
Note that the video from Matt Cutts is discussing internal duplication, rather than content that is duplicated across many domains.
I still feel it's best to let Google crawl and index all those URLs. But I'd also make darn sure that the navigational structure gives very clear signals as to what is the CORE content and what is more ephemeral -- especially if the ephemeral content is going to be a large number of URLs compared to the core.
Google can usually figure out what content is not worth much energy from it, and what is more important and typical for the site's main purpose. If they start to get it wrong, that's when I'd begin thinking about further steps.