Airdrop is a new model of coin distribution among users. There are different rules for each airdrop. But main thing is that users receive coins for free or for meeting some requirements defined by developers
I'm looking into your rank and trying to understand - how come you have Member status and I'm not. My acc is older than yours, and I have enough posts to rank up.
You can only get 14 points for every two weeks, I believe. So, you'll have to wait a bit while your activity points catch up with your post count.
As far as airdrops, as the others have already mentioned, it is a coin that is freely distributed as to an ICO where you have to buy the coin/token.
Some recent examples would be Minereum or DeepOnion.
There do tend to be some limitations - such as rank or account creation date - but they're a great way to build up your portfolio.
If you can't participate in one, though, you can always head to the exchange to stock up early. For instance, your rank won't let you take part in the DeepOnion airdrop, but it's still an early coin and it's a great time to get involved. You can also check out the website at
www.deeponion.org to keep an eye out for bounties and other free giveaways.
