A balance of "reward" and "honesty"

Please reply and help me find the balance points...

If someone gets paid to say good things (spokesman), do you question their honesty?


If they ask you to become a fan, and you realize they got entered into a contest as a result, does it lessen them?


If someone shares something with you in their feed, and they got entered into a contest as a result, does it lessen them?


Think about Facebook games:
When people share "achievements" and get "silver" for it, do you care?

When people write a review for a product, that was given to them, is it less of a review?

When people write a review for a product, and they get a free t-shirt, do you trust the review less?

If someone shares a link on Facebook with a comment, and they get a free hat for doing it, do you care?

THERE IS a line somewhere... where is it?