It is still a very profitable business, but maybe a bit different to what the business used to be like. Not too long ago, CD sales were a big profit entity but now its going down and down because of internet downloads. But then that's just another way to sell - look at iTunes - even though there are so many "free" ways to download music (illegally) - still millions upon millions are buying from iTunes - so sales have moved from high street stores to online stores.
There are still loads of other ways to make money, it just depends if you are willing to do the work and think of new ideas