I listened to an interesting webinar the other night where the topic of discussion was about business ideas and whether or not they are viable. One of the key points was people's willingness to pay.
Many people get so caught up in the fact that they have a great idea, they don't think about whether anyone will pay for it. Its really important to determine who your target market is and whether or not they CAN pay and WILL pay.
I'm sure you can think of examples from your own life. There are things that you don't have time to do, don't want to do, or don't have the skills to do that you will pay for. In fact, if you can find someone to do one of those things you can't/won't do and they do it well, my guess is that you would hire them over and over again as the value they provide you is enormous.
For example, if you can't speak Spanish, are you going to spend hours or days trying to piece together (incorrectly) a letter on BabelFish? You just wasted your valuable time to do something wrong when you could have paid someone to do it right in a fraction of the time.
Think about the services you offer and whether or not you are providing real value. If you are offering a service people are reluctant to pay for, don't worry - just tweak your idea or find a different market.