Free tickets for stuff like this is a bit of a tricky situation. Now we have people who have bought tickets directly and thats great, that money goes directly to the lambo purchasing part (they probably already have that much money anyway) however for people who get deposit bonus tickets, people who earned from affiliates and got it, people who wagered and go it, they are all basically getting a ticket for free without spending their money.
I am not sure if you can get free tickets for the games referrals play. As far as I know the free tickets are only given for the games you yourself play.
However the users don't spend money directly for these tickets, but the website benefits from the wagers users make. The Lambo encourage the users to play more and the website earn more.