Here is the thing.
Yes, we are "product" not customers. But in order to be high quality product that's worth something, we need to be pretty happy. Give us worthless content, unusable web sites, draconian rules, and so on, and we'll simply vote with our feet. 99% of the internet is the husks of collapsed web sites.
So by giving feedback, but expressing what we do and do not like, we help the management. We allow the management to improve the quality of the product they deliver to the advertisers, and we may even help them measure the quality of the product. These forums give advertisers evidence that the "product" is present, and is paying attention. By being engaged, Michael and Kevin show their customers that they are actively working with the "product", the community, to keep the community active, interested, and above all, looking at ads and buying stuff.