These days we pay for everything, but at the same time, we pay for nothing. People don't buy seasons of shows as much anymore, because they can watch them on the internet. Why buy music when you can get it from the internet? Sure, they sell those things on the internet, but whether it's legal or illegal, there's usually a way to get whatever you're after—for free.
The sound effects industry is really no different. Google "free sound effects," and you'll end up with 61 million or more results. One example is http://www.pacdv.com/sounds/. The site boasts: "You may use the sound effects on this web site free of charge in your video, film, audio and multimedia productions." Someone creates these sound effects. Will they eventually be out of a job because no one is paying to use their work? We'll see. It's a changing world, and the Internet is a big part of that.