According to the following study it is taking longer for users to convert in terms of both actual time and site visits.
http://www.dmnews.com/cms/dm-news/e-commerce/41848.html
This is making paid search conversions harder to track because some users are buying weeks apart from their inital click/visit. Patience and in-depth tracking are the keys to succesfully managing a paid search campaign. There is more than just conversion tracking offered by each console that is needed to track the behavoir of users because they only are able to get a certain % of all the orders. The full analytics packages or in-house reporting should be used to give you the visibility into customer behavoir and time between orders.
