my sister works in a betting shop, and the view she gets is a bit different. This town doesn't have a massive drugs problem so maybe we miss out that bit, although you're right about the hard-smoking part. It's the bit of her job she hates the most, after the boredom (gambling holds no interest for her whatsoever). But apparently most of the regular customers in her shop are blokes aged 50+, who often will spend as much on cups of tea as on their bets. If they pop out to the newsagent they ask her if she wants anything. If they have a "big" win (£20 or whatever) they buy a box of chocolate to share with the staff and other customers. From what we can guess, it's basically a social club for retired men, possibly who like the idea of doing something their wives wouldn't approve of.