Like-farming - it's a thing and you don't want to participate. Stop "liking" widespread shares that insist you "Share if you love Jesus" or "Help us get Granny 100,000 likes on her birthday" or "Help end diabetes/cancer/drunk driving by sharing this post".
The posts were created to get likes, so the creator can then sell the Page with lots of likes and followers.
Be a creator, not a follower.
More details at these links: http://www.thatsnonsense.com/like-a-post-for-a-friends-reunion-like-farming-spam-goes-viral/