The best airdrop I had gotten so far was from ODEM about a year ago. I think I got about 200 dollars with in that period. Though I waited for a couple of months before I get to trade it because the first listings of ODEM had a minimum deposit of 500 dollars of crypto currency. If I recall it was Ethfinex / Bitfinex. I felt anxious first because I thought I would be selling on the dump but I was able to sold mine for a great price.