I got a good amount of OMG on that recent airdrop. I had no idea it was coming and unless my friend told me, I would have been so confused.
Google tells me that airdrop was for holders of at least 0.1 ETH at the time of block 3988888 (July 7). It looks like OMG price has gone up 2000% since then ($0.50 --> $10), so that's awesome you got in on it!