First of all, this is a marketing strategy. Way of gaining muvh exposure from the crypto community. The amount you receive depends on the participant itself. The higher the participants, the lower the reward.
Then what guarantee do they have that those participant they havedistributed the free token to will take step to directly invest more in the project, although it works for some projects, if the participants see that it is a coin that is promising and have a real life working product for future growth, they will be encourage to add to the amount of airdrop token they get since most airdrops are usually little in quantity.
This method doesnt work for all projects as you dont know how financially buoyant the participants in question is for them to commit their fund directly when we still have so many projects in the market that are doing the same. So, how many of those projects will the participant invest in?