Poor statistics on the chance of winning aside, there is one reason for me to spend $1-$2 a week on tickets: Having a ticket ensures you have a chance of winning, while not having one ensures none at all. Losing the $50-$100 per year isn't too big of a deal for me, especially for the entertainment value.

If you bet on sports with your friends, you get the same entertainment for lower cost.

Only if you enjoy sports. Also very few sports bets pay out a million times the money. Even a bet like France beating Canada in the ice hockey world championship only pays 33 times the money, and the prospect of winning $66 on a $2 bet is hardly exciting.

But winning those $66 while your friend just lost $2, (or the other way round) could be fun ;)

Sports become far more enjoyable when you bet on them.

I buy one or two lottery tickets every year. This gives me a non-zero chance of winning, with negligible cost. Going from zero to non-zero chance is a more important step than the one from almost-zero to still-almost-zero chance that buying 1 ticket a week would give me, at least psychologically.