I think experience plays a major role here as a determinant factor for a bounty hunter to double as an ICO investor. In most cases, some bounty hunters may be ok by only campaigning for ICOs and getting rewarded while some, from experiences would see the ICOs as one that is promising and so would invest by buying more token in addition to that which they would get as reward for campaigning and so rather than only campaigning for the ICOs and get rewarded they go extra mile to buy more in addition.