And you could use systems built on top of bitcoin to make micropayments, like when you have a webwallet that allows fee-free transactions to other users of the webwallet. But then we can get into an argument over whether that is actually using bitcoins. Whatever.
Off-chain is probably the best solution for micro payments. Either by a centralized web wallet, or just by buying a larger amount of credits from the service provider directly. E.g., you want to access a website where every page view costs BTC 0.00001, you send BTC 0.01 to the provider's address and can access his pages 1000 times with your payment address. That way, BTC could actually become an enabler for simple, quasi-anonymous micro payments.
Instead of sending 0.01 BTC buyer can send 10 USD. The effect is same with FIAT. So how can it be an advantage ?
How do you instantly send 10 USD to a website? Quasi-anonymously on both ends? No registration required? With no means of charge-back (that's extremely important for any provider of digital services)? With absolute proof of payment? At a low price?
A simple Bitcoin transaction allows all of the above.
How do you instantly send 10 USD to a website?
When I buy domains using my credit card, I buy them almost instantly. For Bitcoin transaction buy needs to wait for confirmations.
Quasi-anonymously on both ends?
Anonymity is not required for a white collar buyer.
No registration required?
Registration is not required even for PayPal payments. Registration is part of a total application, not payment.
With no means of charge-back (that's extremely important for any provider of digital services)?
This is NOT a buyer's advantage.
With absolute proof of payment?
Credit card invoices are no less payment proof. The difference is, for Bitcoin, it is public.
At a low price?
For Bitcoin transaction network fee is required and for a low transaction amount this fee is significant. There is no individual transaction fee for a credit card payment unless u use PayPal or similar service rather than direct bank gateways. Credit Card service charge is applicable for holding a credit card itself.