My sites have recently taken a major drop in traffic from google. Both sites are over 8 years old have ranked good for years. The only thing I can think of that may have caused this is the link list cgi program I use produces duplicate meta titles and descriptions on all continuing category pages. This results in hundreds of pages with the same meta's. Do you think this could have caused the sudden drop in traffic? My google traffic dropped by 70% or so.
I doubt it too - I only recently saw duplicate meta tags flagged in Webmaster Tools as a potential issue, and they related to a site of mine that is indexed just fine, whereas I have sites being slapped lately that have nice unique meta tags throughout. Seems to be a bit of a shake-up going on with Google, bit of a worry because it's directly hitting my best-earning sites, like eBay auction sites... Once more we are the mercy of the Google-Beast...
Do you receive all your traffic from Google? It's most likely an algorithm change or an issue with your robot.txt file.
Most of my traffic is from google around 70%. I don't think it is a issue with the robot.txt file since I just have it set to disallow /cgi-bin/. This sudden drop in Google has happen to my two sites every year around June to July for the past three years. A couple times the traffic has came back in a couple weeks then other times it didn't return. I can't hardly believe it is just a algorithm change because my keyword competitors didn't seem to get hit.
Google flag duplicate meta and duplicate title at Google Webmaster Tool, so IT MUST BE MEAN something, avoid it if you can.
They do flag it, but it says something like "better title/description makes it more likely people will click on your site". Unless there is some deeper nefarious purpose it sounds reasonable to me.