It is just brand awareness. By relatively low value advertising you expand the brand awareness and strengthen your position.What can teams give back? An enforced brand loyalty, whereby you give the team a discount to encourage them to continue buying from you, with the threat of the discount being withdrawn if the customer is unfaithful. For 90% of teams, that is all. There is very little added value that any but the top teams can bring to a paintball brand in their own capacity. A domestic Div 2 team will not increase a paintball brand's exposure in any tangible way, so the concept of sponsorship makes no sense.
Now it's possible that outside sponsors can find value in lower-ranked teams, by showing their name by any means to an audience that otherwise would not see it, but on the whole paintballers have no idea how to sell themselves, either to potential sponsors or to a sponsor's target audience, and any marketing exec worth his corner office can spot this a mile away.
Some companies will opt for this to keep the brand in mind of people.
For example Sony has past few years lowered their brand awareness and had to work very hard to retake the market share. Continuous advertising across variety of demographic groups will keep the brand known.
So paintball will not make big waves as you said but will keep the brand alive within certain population group.
Basically you have to make the marketing people believe that paintball is way to go in their campaign to dominate the world (that’s what they want anyway)
Market penetration within certain group might be also option, with one slight problem; you would have to know if new product is coming out as paintball will not be their top list of market penetration tools...