I just looked at the site and the reason they are "giving away" a free companion ticket is that they are charging WAY TOO much for the first ticket. Living in DC, I would have to travel to either BWI or Richmond to depart.
From BWI to Las Vegas = $500 (for the first ticket)
From Richmond to Las Vegas = $520 (for the first ticket and they only match the first $500 for the companion ticket)
Funny, I thought I could get two round trip tickets to Vegas for less than $500.
I just looked today at the offer, so it is still available if people want to check it out.