Your first instinct is what I would go with as well. As an ex affiliate marketer I can say is that in the beginning of a campaign you are going to lose money most of the time. But in return you are getting all this valuable data of where your campaign is converting and where your campaign is not converting. With that data you make your campaign profitable. You can go with the other way by adding a few individual apps but I just see that as time consuming where you can test out all the traffic right off the bat in the beginning.