I'm sure the economy plays a big role in company's decisions re: prizes they offer. If smaller or fewer prizes are what's needed, though, so that they can keep their employees working & paid their salaries, then I can deal with it on the sweeping end, anyway.
These sweeps are all advertising for them, with the goal of getting more customers & garnering more good will & customer support. If they find that their advertising techniques are not working, I'm sure that they will try to make changes that benefit the company. So, if entering daily doesn't seem worthwhile to you, you can let them know by not doing it. They'll look at their numbers and, if they've dropped enough, try to get the numbers up again.
Personally, though, I'm still entering as often as before. It's a hobby for me and, for now, it's still fulfilling & exciting.