Bidding by ROI Percentage in Adwords

UPDATE: on August 8 this year I posted this initial blog post, now I see Google is announcing the feature! Cool - http://adwords.blogspot.co.nz/2013/10/new-flexible-bid-strategy-and-webinar.html

Feature request: Dear Google, I would love to be able to bid by target ROI percentage in Adwords. The idea would be to set a target at the campaign level using a percentage ROI you would like. I have a client who doesn't want to run ads at less than 500% ROI, and this is something I am getting done using Google Analytics, but it is kinda tricky as I need to switch between GA and AW, boosting ad groups with high ROI, and pulling back on ad groups with poor ROI, working to increase the overall campaign ROI in order to acquire an increase in budget, and turn AW into a money printing machine.

ROI = return on investment.

ROAS = return on ad spend.

Thanks, Tom.