Thanks this clear introductory write-up on airdrops. I was having trouble understanding the concept, but recently some airdrops like the ByteBalls one, which paid a nice amout of token relative to Steemit reputation, and the upcoming 1:1 HNT for SP airdrop on @steemhunt have helped to demonstrate the airdrop concept in action. I also signed up for this BCIO airdrop account using your referral link. Thanks again.