There are several ways to earn token/altcoin free except bounty campaign.

Airdrop - This is one of the easiest way to earn tokens as well. As an example some of the airdrops have to connect your Facebook,Twitter,etc... after you can earn free tokens by sharing /retweeting their posts.

Mining - There are some several application for your PC for mining then also you can earn free tokens.

But keep remember those are not much than Bounty campaigns if you earn more tokens with more profit you should find a good bounty campaigns.
Hope this will helpful to you.