It appears gay marriage is going to happen soon and once it does happen finding a wedding venue that isn't booked out is going to be ridiculously hard. As it is people have to book the most popular venues more than a year in advance. So if all of a sudden thousands of gay couples who haven't been able to get married decide to get married, there will be a period of intensely crazy competition. In this I see an opportunity.
I could book out at all the slots at the most popular wedding venues and auction them off to the highest bidder. Instead of $100 a head, people will be paying $250 a head and I will be pocketing $150 of it. Genius.