Micro earnings is the easiest way to earn bitcoin though it is a very time consuming. Mirco jobs, bitcoin faucets, paid to click websites are forms of micro jobs. Completing their small task, they will pay you bitcoin. But just a very smal amount of bitcoin.
I think you can no longer consider this "profitable". More like "wasting precious time" now. When I first heard of bitcoins and tried to look for ways to get them, I tried these. Cannot remember the names but there was one where you simply read books and click on ads, one was a radio station, another was roulette with free tokens daily. All required getting a specific amount of satoshis (usually in the 100k range) to even cash-out and send it to your wallet. Never got any out of those.