Some kind of chicken and egg problem

I agree with Joel. The key is that you need to manage it for them right now if they're not doing it themselves. It's a lot of work. Once you show them it's working you can then push them to do the management. In the long term, if they want you to keep managing it, there's an opportunity for you to collect more revenue from them.

If you don't want to do this, it looks like finding a way for them to stay interested and participating is going to be one of the most important aspects of your business. Think creatively, and consider it more of an opportunity than a drawback. Think about what other busiensses do... some ideas might be crowdsourcing, badges, utilizing social networks, etc....

Many new business encounter this problem. Obviously I do not know your business, but there are some things you might want to look at:

• Automate: Would it be possible to make sure that your website is automatically updated through e.g. a XML feed. You DONT want people to book for a sports field that is not available;
• Compare: Have a look at e.g. the hotel industry to come up with some idea's how to work this out. The hotels are listed at many different booking websites such as booking.com, but they obviously do not use different backends for each website they have listed their rooms;
• Provide: Are they already using software for their planning? Or might providing an easy-to-use package an extra opportunity for you?
• Provide: Try to provide extra services such as an online payment facility. It gives your partners (read sport fields) and extra reason to work with you since they always have their money up-front and have to deal on the financial with one party only.
• Spread: Try to affiliate your product through third party websites. This can be set-up quite easily. Provide XML data, or create widgets. Do something that adds value to the third party websites and utilize their user-base.
• Make sure that the sport fields know your intentions. This exceeds informing them about your website and what your website does. It is about you working your ass off to promote their business. And keep them up-to-date with the things you are doing. So stay in touch with your partners (Don't SPAM).

You can hire someone to input the data for the first three to six months, so they really don't have to do anything until you've got the system up and running.

Your business sounds a lot like OpenTable, which tried to do the same thing with restaurant tables. They spent a ton of money and many, many years trying to get started, but now they are a very valuable public company. OpenTable did this by giving the restaurants a free computer system they could use to manage all their reservations.

Thank you everyone, i really appreciate the answers. I desperately needed valuable opinions.

So, here is what i thought i can do, considering my limited money:

1. I will try to find out how similar businesses solved the same problem

2. I will encourage them by promising some gifts if they use my program for some certain time. Like an e-scoreboard (if i can find a sponsor for this scoreboards, like coca-cola:). This way, they will certainly gain something, even if the system doesn't have enough benefits.

3. Hiring people to do the job seems like the direct solution. I can hire some people to call facilities and update the schdule over phone. But this will still be extra work for facilities. And an annoying one maybe. So im not sure if calling approach will work for 6 months.

   So, i thought, maybe i can pay extra money to workers of the facilities for doing my job. This could be a solution for some of the facilities.

If i had enough money, i might give them an ipad, as long as they are my partner. This could make at least some of them to drop paper. Fancy enough to make them drop paper and its usage is paper like.

I will keep this thread informed about the results. How i solved (hopefully) this problem.