I've been having a discussion about session beers with a couple BeerAdvocates, including Todd Alström, one of the founders. Why don't session beers sell, is the topic, and after some discussion, I pared it down to these three questions:
Do they not sell because people want more alcohol? (Brewers have told me that when people find out that a beer's low-alcohol, they shy away from it.)
Do they not sell because they're unfamiliar styles and flavors? (American craft brew drinkers have been exposed to a lot of piney/citrus American hops and clean-fermenting American ale yeasts; they often find beers brewed with the more characterful Brit ale yeasts to be funky, or just plain wrong.)
Do they not sell because the ones that are being brewed are just not that good? (A real issue: it is not easy to brew a good session-strength beer...or so I've been told.)
Interestingly, Todd raised a fourth issue: in Boston, he says, people do want session beers, thirst for them, and drink them up every time they come along...but the brewers just won't make them. All too busy following the latest hops/alcohol trend, he says.
Which brings up the old story: selling craft beer is all about education. Usually that means the brewers teaching customers about how to enjoy different -- session! -- beers, but if needs be, maybe the brewers need to be educated by customer demand.
What's the story where you are? Do you get a fair number of session beer choices? Do people drink them when they're available, or are they a brewer's conceit? Do your local brewers make enough session beers? Do your local session beers suck -- sour, insipid, over-hopped, under-attenuated? Tell us the story...and maybe some brewers will give a listen.