For a regular user to use Lightning, they would have to run an always-online instance of lnd--a very memory-intensive Go program that also requires a Bitcoin fullnode (300GB) or the experimental Neutrino light node either of which also has to be always-online. The average internet user has never typed a bash command so this is a pipe dream. Or you could have the alternative which is to push people onto centralized Lightning-like (but better, more polished) services run by the likes of JP Morgan. (It's my suspicion that focusing hype on Lightning instead of scaling Bitcoin Core was a way to sabotage it in favor of paid services of a certain company that most Bitcoin developers are employed by but I digress.) Micropayments in general is a bad idea which the market has rejected time and time again. If you really want to do something like that, just do it the same way all billing works, add it up and notify the user with an invoice at the end of the month or year. That could be integrated into browsers without being tied to a specific payment method or forcing payment. I don't even want to imagine how rich hackers would get if every web browser had a code path that transferred real money.