The problem with these big payout incentives is it doesn't get people in who think it's a government conspiracy and they have no chance of winning anything because it's rigged.
For those people it would be more effective to give each person an immediate gratification reward, partner up with some popular merchant like Amazon.
The thing they should NOT do is entice people who have just been vaccinated, so they are still potential carriers or vulnerable to catching covid, to go out around others (waiting in the long line for their free joint where they are far less likely to be monitored like in the vaccine line) who were also just vaccinated so also still carriers or vulnerable.
It was an idiotic idea by a clueless government to offer something that's going to line up a bunch of druggies who are not all that likely to keep their masks on, likely even passing the joint around to others.
Stupidity for the win! It could work though, if they made it a term of fulfillment that a voucher or proof of vaccination date is needed and only redeemable starting 2 weeks after the second vaccine shot, so it's had the best chance to cause sufficient antibodies.