I'm in my mid 40's and get them, too. I suppose they know I'm male, but not necessarily my age; I do not think I'm the target for these as I do not watch sports at all nor game much.

My point here is that I get these ads and I can sense that they are targeting young men.

Do the honors. Click. Sign up. Use free bonus. Do some arbitrage bets (use bonus to bet on A and bet on ^A elsewhere). Cash out. Close account. They now lose money.

I get tons of them too. I don't gamble or play games like that.