The little bit of money you are hoping to get from the sponsor wouldn't be enough, for me, to offset the disadvantage of losing amateur status in AKC field trials.
If you decide to go through with it, I suggest using chairs for your ads. Your chair is out there all day, even if you're not. The other ten people in the gallery notice this chair and the ad. Inevitably you will forget your chair at the event, somebody adopts the forgotten chair, you whip out a fresh chair...now you are up to 20 views!