Some services have both, but they generally have much lower league prizes. They would need 2000 people just to pay the prizes. They still have to pay their advertising costs, overhead, salaries, phone bills, mailing costs, etc., before they make any profit for themselves. Ask if the prize money is already available and guaranteed. Then ask when the prizes are actually paid.
Some services count on income from football entries to pay out their current baseball prizes.
If their future business does not meet financial expectations, you might not get paid. Some fantasy sports services promise large grand prizes based on a certain number of anticipated customers. There is nothing wrong with prorating prizes, as long as you understand how it works when you sign up. With Statman-Plus, if your team earns a prize, it typically gets paid with your last update of the season. Professionalism is important to us, so we don't keep you waiting for a prize that took you all season to earn.