Hello, from my small knowledge in Airdrop, I think Airdrops are only good in the path of the project and not for people participating in the airdrop because in the part of the Project, it increases the reach of the project (project awareness and social media reach increases) and on the path of people participating it only gives them small rewards which makes it more favorable to the Project.
Please share your view on this so i can update my knowledge if am wrong. Thanks
Most icos give conduct airdrop campaigns because they want popularity for their projects and not necessarily because they want to give free tokens out. Some also do it because they want to increase the number of holders and traders for their tokens so that there can be adequate buying and selling transactions on exchanges.