Items you find here, and that you thus should be able to get for free from the one posted the message, should be used by yourself on a non-profit way. By this i mean that if you receive like a free elite-tome you should use it on your own character instead of selling it to some random person in one of the major cities. Or ofcourse you can give it away for free to someone else as well.
So in short peeps that are giving away items for free are doing so with the thought that this item is of help for that person and not with the thought to make that person rich