Many are moving to a subscription model per month (simple and predictable pricing) — think Spotify, Wall St Journal, etc.
But curious, what kind of things would you like to buy at 50cents or less online and that you really can't right now (either as part of a larger bundle or a subscription)?
Also, the blockchain is not particularly good at managing micro-payments. First because of miner fees and second because micro-payments without fees open the door to blockchain spam. Most of the bitcoin micro-transactions done today are centralized off-the-blockchain transactions.