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?