I just read a very interesting blog post from the Rimm-Kaufman Group about the changes that Google had made to Broad match keywords and the resulting effects. In the article they point out how the performance of broad match terms has gone down and that they have been noticing some troubling incidences where the broad match ads have been appearing when better and more closely matching keywords (and therefore adverts) have been available.
They believe that this started happening with the change to a ‘1st page bid’ rather than a minimum bid, Google is ignoring/not seeing some of the more exact terms with lower bids and is instead posting the broad match adverts. This idea certainly tallies with what I have been seeing in my analytics; looking at the actual search queries for broad match terms has thrown up example after example where there was a better matching keyword and ad group for the search. The result of this is that we, the advertisers, do not get the most suitable advert appearing for the viewer, Google have less relevant search results and that in turn will make the search less efficient for the consumer.