This month is Make May Mild Month. The idea is to encourage people to drink mild to help boost the declining sales of this style of beer. Mild tends to suffer from an image problem, being seen as an old man's drink, which is a bit odd, as a lot of old men actually drink lager. Lager was presented as a clean new drink in the days when processed cheese, meat and sliced white bread were seen as the future; it was reliable and consistent, unlike that boring old cask ale, which was thought to be on the way out, an attitude confirmed by the fact that it was often not well kept. If a modern real drinker could travel back the the fifties and sixties, he or she would, I believe, be sadly disillusioned with the real beer available. The reputation of mild wasn't helped by the fact that licensees often put the dregs from all other beers into the mild cask. This isn't an urban myth - it actually happened; mild was not treated with respect. The poor image of mild still remains, whereas real bitters, stouts and porters seem to have been largely rehabilitated.
Modern milds are quite superior to what went before. If you want a reasonable example of old style milds, try Tetley's, which actually tastes better than Tetley bitter, but which I find unremarkable, thin and weak flavoured - having said that, a lot of people still like it. Milds should have flavour, but being more lightly hopped, shouldn't be particularly bitter. Because of their lower strength, they are sensible choice if you have to drive or go back to work. Milds I do like are Moorhouses Black Cat and Prospect Nutty Slack, and I know Theakstons Mild has its advocates.
The only thing I don't really understand is why May should be Mild Month, seeing that it is often considered a winter beer. In May, the golden ales that herald the summer are making their appearance, which must surely push mild out of drinkers' minds. There is an on-line campaign to Make March Mild Month (link here), but it doesn't seem to be making much headway.
It would be a pity if mild disappeared completely, especially now that small brewers are producing good versions of the style.