The more Likes and Shares you get, the more you boost your Facebook Edgerank, which means the more people Facebook will push your posts to.
The spammers have figured this out. That's why you see so many "If I get one million Likes, I'll stop texting while I drive" and other ridiculous messages.
A photo with a person holding a sign. The message tugs on your heartstrings. "If I get 50,000 Likes, my dad said he'll quit smoking."
People are gullible. They are easily chumped out by emotional appeals. "Let's help him quit cigarettes" someone posts as a comment. "This is a good cause that I can support," chimes in another well-meaning person.
But all they're doing is helpin a spammer expand his reach on Facebook. The message is a lie. It's designed to compel you to click Like and Share, which sends a signal to Facebook Edgerank algorithm, which will be tricked into thinking this spammer is really popular, really posting valuable content.
It's an effective scam. You have to admire the sheer diabolical brilliance of the scheme. But if you ignore this warning, and persist in trusting these spammers and their clever messages, all you're doing is helping the spammers.
Don't be so stupid.