Did anybody experiment with different ways to use 'FREE', Free, or free?
Heard some rumors that capital letters are not really appreciated by fb :P.
Any recommendations? Does it matter in cpc or earlier ban?
Thanks
Its all about testing and comparing metrics.
CAPITAL LETTERS ARE VERY SPAM SENSITEVE though
and users dont really appreciate it
I would rather say, that the word FREE is a very common thing? so therefore ok?
I was more talking about fb, not liking it 
The answer is clearly going to depend on your audience and the specific offer you are advertising. Only tests will show what works for you.