What makes people share new opportunities for airdrop offers?

It's no surprise that people keep sharing their referral links in the hope to earn some rewards when people sign up using their referral link or promo code. That's the whole purpose of referral reward anyway.

But what if there is no referral reward for you? Would you share the same among your friends and followers?

May be, not! But if the offer is really too good that you won't like your friends to miss on it, you may make some effort to share that too. After all, that will earn you some bragging points and will strengthen your relationship further as it proves your helping nature.

But what if you're penalized to share some airdrop offer?

Yes, penalize in fact! I mean like Keybase kinda airdrops.

Keybase offers a limited amount of coins that is distributed equally among all its users. So effectively it means that more people joining it will actually decrease your share in airdrop. Thus more you share, less you get out of the total bounty.

I often keep wondering on such offers. What makes Keybase come up with such a reward offer to promote their wallet! Why would anybody like to share such an offer!

I really don't know what leads Keybase team to think that this would be a successful model to promote their product into masses. But it seems that it works.

In preceding weeks, I've seen several people posting about the Keybase airdrop. Some even shared the news when they receive $20 in Lumens. Perhaps $20 is too good to not to share or may be because XLM is comparatively an established coin that is already listed on major cryptoexchanges. Whatever it is, but people are sharing it lovingly though it's decreasing their own reward with a slight percentage.

Perhaps they think their individual contribution in promoting will result in very negligible decrease in their reward, so why not share it. There is always some cost for being nice and helping someone. So why not! But collectively, the effect is a huge reduction i reward as thousands of new users sign up for it.

So I just want to ask the marketing geniuses here, what makes companies to come up with such schemes and what makes people to actually promote such scheme in spite of the in-built penalty for promoting the same?