i got only 0.39$ for my 127 posts

this is for sure because you keep doing only short discussions and myLot system doesn't rewards you with much cents per post. I've noticed that we are payed from 1 cent to 20-30 cent per post. If you post longer messages you earn much more. If they are interesting, people can rate you positive and you earn more. If you post is not interesting or very short, you will earn nothing! So think before posting useless things!