Though some people say joining airdrops is just like beggar in crypto world, if you just have the determination and the patience, you could earn a lot here in bitcoin.
Beggars in the Arab is not terrible, on vice versa they can earn higher income. 
Rare one for none, airdrop too. When someone find out a good airdrop and earn some money from this, they will tell about it for their friends, relatives or in socia media. That's a good way to popularize ICOs.