U.K. Gambling spend £6.8bn 2013/14, excluding the National Lottery, which looks like it will be £7.2bn 2015/16. So £14bn a year (probably more, I think gambling is growing exponentially). Which is £269m a week. I don't gamble much myself, just a flutter with cash I am prepared to lose when I'm actually at the races, which is hardly ever. I don't have a problem with gamblers though, their choice. Of course for some it is the road to ruin, but you could say that about dozens of things. The amount of gambling advertising is another matter, very aesthetically unpleasing. Plus high streets full of betting shops and pawn/loan shark shops next to each other. Horrible.
High street betting shops exist in their high numbers primarily as sites for the highly addictive roulette and casino game machines (FOBTs or fixed-odds betting terminals) which have been described as the crack cocaine of gambling. I suspect that the vast majority of the profits made by betting shops come from these machines. The government should legislate to reduce the numbers of them and the maximum stake, which is currently £100 per spin. These things are a scourge on society.
http://www.bbc.co.uk/news/uk-33566034
http://www.stopthefobts.org/