Add a New Cost Per Click Parameter :)
It would be game changing if a new parameter was added that would track cost(one of these: https://advertise.bingads.microsoft.com/en-us/blog/post/march-2016/new-tracking-parameters-for-urls-in-bing-ads) This would give the capability to pass a cost parameter that would pass the price of each click to a tracker.
This would then give me and many others so much more flexibility. In my tracker, I can now see the conversions & revenue I get for each keyword, campaign, ad group, ad, etc, from other parameters, but with this feature I would then be able to see the profitability of each of those since the cost would be shown as well. Right now since the cost can't go through the tracker, I have to compare everything manually in Excel, which is extremely inefficient when you have thousands of keywords, and hundreds of ad groups.
Hmm, but would you really like to let your competitor know what your actual CPC is by just let him clicking your ad and read your URL?