On talk radio, some talking head was chatting about how the world of Fantasy Football is out of control. The billion dollar figure comes from publications, software, and advertisements. This does not include side gambling and entry fees that some leagues introduce.
Other ways this is getting out of control is the fact you buy insurance for players on your team. Let say you draft Brady and you have some sort of payment in your draft. Either an entry fee or a cost to draft someone in the early rounds. If Brady is out for 6 or more week, you can guarantee the reimbursement of your entry fee and/or any cost to acquire Brady.
There are also litigation sites that are cashing in this industry in a big way. Fantasy Football is a biased setup, period. The commissioner will have a team in the league. So, if you dislike the way a trade occurred, you can pay $15 to have a lawyer and some of his judge partners mediate your dispute. You can also pay $100 (or some flat amount) for a season of disputes. Smart thinking by someone, and pretty easy cash flow.
I have enjoyed fantasy football for many years now. However, I tend to stay away once entry fees are thrust upon the managers. However, I would never pay for the above two services. Kind of wish I got in on the ground level with some of this stuff. But, with this being a billion dollar industry for about 4 months of actual work, there is enough money for everyone.