In a general philosophical sense, the concept of currying favor with retailers of your product via such "payola" is no different from a mega-retailer offering you a discount-club card membership, or Amazon's retailers offering free shipping, or McDonald's offering a toy with a Happy Meal, or even a bar offering a Happy Hour or Ladies' Night. Or even the occasional complementary drink from a bartender at your regular pub. The above practices, in a sense, are just as unethical and immoral as the practices being discussed in the article in DCBeer. The fact that such "payola" is downright prevalent in the alcohol business bespeaks much more the profit margins and revenues involved in the alcohol business and the return on marketing from such practices (occasionally qualifying for the term "obscene").
I disagree. I am the "end user" of beer. I am also the end user of a discount-club card membership, hypothetically. In order for the above analogy to work, the retailer of beer would have to be the end user. But retailers are not. I am. You are, maybe. Oh, and that discount-club card membership, it's not free. It may not cost you any money, but it will cost you some privacy.
Now we will add some more nuance.
They [both brewing companies and grocery stores] want your trade. They're offering you incentives to do business with them. You don't have to take them. But you'd be a fool not to take advantage of such offers, if they are of use to you. (As opposed to, say, the Turnip Twaddler that comes with the Ronco Tomato Musher.)
So one is illegal, the other is not, and there is an equality of opportunity here in that anyone may sign up for a discount-club card, and that even a craft brewer has the right to "sellout," to become popular and play with the big boys, Budweiser and MillerCoors. However, let's play the libertarian thought experiment and eliminate the government, or at least get it to the size where it can be drowned in a bathtub. Here, the equality of opportunity to sellout wouldn't matter. Rather, the larger brewing companies would simply "capture" the state, and use state apparati for their own purposes. To me, this is a central flaw in libertarian thought: the state won't wither away, it will be propped up and used by those who seek to use its power, or vestiges of power. Don't believe me?
One more thing, of the craft brewing companies he mentions by name in his write-up, at least one of them was implicated by a distributor I spoke to when researching the DCBeer article.