If you have some marketing skills like "SEO" or if you know how to promote offers in social media you can try some CPA networks that pay in bitcoin.

Check this threads below.

- https://bitcointalk.org/index.php?topic=978258.0
- https://bitcointalk.org/index.php?topic=790216.0
- https://bitcointalk.org/index.php?topic=3344045.0

Also, check this section https://bitcointalk.org/index.php?board=212.0
You can earn by doing captcha in some faucet site but you can only earn a small amount unlike on CPA networks.