I focus on the translation campaigns (dutch). A translation pays +- 3 ETH on average. I have only started (only 1 translation has been paid, I received +-2 ETH), but as I can make up to 3 translations/month (currently working on 2 more), this would get me 9 ETH/month. As not every project is succesful, let's say I will receive 4,5 ETH/month.
That is a really great income. I can earn only around $500 - $1000 working very hard with Social and Signature campaigns.
I will try some translation campaigns in the future.]
Thank you so much for your information.