Adwords experiment

I have started an interesting experiment with AdWords service of Google. I have chosen a high quality software product. Selected the right keywords, made geotargeting & started advertising. Have made a campaign with 2 adgroups (one for broader keywords, another for the best matching keywords). These groups compete against each other. Its really interesting that broad keywords, with terrible CTR`s & with tons of impressions are performing better. The CPC is better, so the price of clicks is for astonishing 30%. lower. The purchase-quality of clicking users could be worse of course, but will continue the experiment & report the results.