I guess you don't know that Coinbase is not supported on some countries so the members have to make sure before joining that the coinbase is accepting their country .
Coinbase is accepted only in 32 countries https://www.coinbase.com/global?locale=en and there are 195 countries in the world  
Good to know. You're welcome  .

Edit :
Another hint :
For example India, i think, its not supported on Coinbase but a big percent of money earning online (GPT) clickers are from India ,so you lose a big audience there  
You're welcome  

Another hint:
Coinbase needs to forward periodically the US accounts amounts lists to the IRS . So i would be surprised if any american people as micro earners will still use Coinbase to pay taxes .
You're welcome 

Another hint ,Coinbase has high fees on withdraw.

My opinion,
Bad move to choose Coinbase