I've heard of a few sites adopting the 'pay as you enjoy' model with Lightning, but haven't seen any where readers specifically stream sats for every second/minute they're on a webpage. Mash advertises this function but I couldn't find it in their widgets, only pre-pay-to-reveal options.
I think stream-as-you-read could be a great option for blogs and educational sites, because readers wouldn't have to pay for anything sight unseen, but they also wouldn't have to get anything useful for free - their payment would be exactly proportional to their utilization.
If Mash is advertising it, I assume it's possible or coming soon, but has anyone already seen any sites like this?