Yep, this is known. The small pop in stock price happened when rumor of a possible deal with Coke happened many months ago and you can see where the stock is now from then. Coke will make the only money to be made from sales of this product.
The benefit to Caribou is as you say, to simply get their name out there in a wider market, which could, over time, possibly lead to a few more people trying their product. The important factor is how will that increase SSS, which are in decline basically because the larger percent of people who try Caribou don't go back.
I think we all agree that this "Coke" deal that some are cheerleading here is a non-event for the near term, at least, so don't expect a positive move here based on that.