Directly buying bitcoins, is the fastest and easy way. But there are others alternatives, like:
Faucet, Offering your services, Signature Campaigns in this forum, etc. There is A LOT of different ways
Faucets produce dust (very small satoshi amounts) which would raise your transmit fees - effectively you may end up losing money if you have faucet dust mixed in your wallet.
Mining, selling goods or services for
BTC are the common ways of earning
BTC. Easiest method to acquire would be to buy it on an exchange.
The faucet income is a dust now. But in a few years/decades, the bitcoin might increase in value, the dust will be valuable.