Law of reciprocity. You get a free stick and feel obliged to say good things about it.
This isn't entirely true. They gave them to the hosts of Beer League Talk so we would talk about the stick on our show. We did feel obliged to do that but we were honest. We said some pretty bad things about the QRL. One of us broke 2 of them in the less than a month. We said the stick wasn't great and we wouldn't spend $300 on it. They then sent us the Alpha and for me I loved it so I gave my honest thoughts about it. We were also chosen for this season but have yet to get the sticks.
Maybe individuals feel obliged to say nice things about it so they continue to get picked but we don't. We feel we have a responsibility to our listeners to be objective and honest. We are upfront that we got the sticks for free and are honest in our review. If we don't like the free stuff we say it.
As for getting picked I can't tell you a fool proof way to get picked. It seems like they pick people who are ultra active on social media so they ensure that their product will be talked about.