Why is Advantage/Fox e.g. car rental half the price of the market leaders? [closed]

I just arranged a rental car pick-up at MCO for this weekend. In order to get the Hotwire "hot rate" you need to wait until after you book to see what the company is. I have typically been lucky in getting those rates from the market leaders e.g. Budget, Hertz. But this time I got Advantage. The price was almost half of the market leaders.

Why is this? Is the service experience rated poorly, hence the low prices? Is it because of a lack of advertising?