[ylere]

Fixing the missing links in the billing chain is what we have been working on at Wingback (https://wingback.com). Agree that the actual metering part is not that hard to get (and having a standard here would be great!), but using it to correctly enforce entitlements in your product and accurately bill your customers who might be on all kind of different plans, models prices and discounts over a large number of metered (and umetered) features is.