Robert_Charlton - 10:10 pm on Jun 19, 2013 (gmt 0)
With extreme localization of serps, along with other types of personalization, rankings that you may be able to see no longer tell the entire story.
Some members have reported an increase of traffic with no changes in ranking. So it's reasonable to expect the opposite to happen as well.
There's likely to be a broad range of intentions built into some queries, as well as many different types of searchers, so your site needs to anticipate searcher needs and satisfy them if it's going to thrive in an increasingly personalized environment.
Have you looked at various types of traffic and conversion funnels in your analytics to see what might be going on?