How to decide when to reject an order

A month ago we (a group of four IT people) founded a small company here in germany. Two of us still finishing up college and myself and the other collegue have a full time job on a big european IT company.

We're acquiring a lot of clients and already received a great feedback for our work.
Now, I a lot of new potential customers are knocking on our doors and are willing to spent a lot of money on our products. But, given the limited time, we're able to spent (about 5-10 hours a week after work and on the weekends), we won't be able to accept every order we receive.

What are your criteria on order rejection? Any advice on our personal situation?

Thanks!

(and please excuse my english :)

Since you have A LOT of clients who are willing to spent HUGE money on your products, what's the thing that stops you guys from quiting your job/school and to go full time?

You can always go back to school/ find another job should your venture fail ( which is highly unlikely as you already have a lot of customers who are willing to spend big money), but you don't always have this opportunity to make your venture big.

What about hiring people? Perhaps some college interns or part time IT techs. If this is not feasible and you must do it yourself, then you have a choice to make.

I can understand the school part, but the decision is simple for the day job. Either you follow your dream and take a leap into the unknown, or you continue the daily grind at your cushy office gig. Making that commitment is the first step to being a true entrepreneur and it will ultimately decide the direction of your company. Do you have what it takes to make the tough call to get the job done? Its scary and nobody said it would be easy. The worst case scenario your company fails, you go find another job, and leave with a great experience had. Best case scenario your company flourishes, you are your own boss, and make 100% of the decisions in your life. (Unless you are married, in which case you are back to 50% ha!)

I understand the importance of being well educated when servicing the German market, although you seem to be doing okay so far bringing in business. However, as per Joe's answer, there is a sense in which being an entrepreneur is about being prepared to turn your back on the conventional job market, and standing or falling on your own skills and determination alone. If you're not up for that at some point, then maybe you're better off staying employed. Neither course is wrong - different things suit different people - but trying to mix the two is unlikely to work long-term.

A bit of practical input based on my own experience. Seeing as you have the luxury, choose your customers based on their ability to help your business develop. That doesn't necessarily mean going with the firms offering you the most money, but rather firms that have requirements in line with your long-term product strategy, or firms that bring such tremendous kudos as customers that the mention of their name makes your future sales so much easier.

Again picking up on Joe's point, also look for projects where you can use outside help and get the customer to pay for it, whilst building out the product at the same time. Be very careful about that one "big-name" customer who wants the earth, especially if much of what they want isn't strategic to you - they can kill your business with their constant demands (my previous business once had this experience with one of the 'big 4' consulting firms - not nice). Along this line, look for firms that understand where you are as a business - ones that you feel you can work well with and are prepared for a bit of give-and-take.

A final unrelated point, possibly superfluous as Germans are typically very efficient and organised - make sure you have your basic support systems in place (see for example the Joel Test ) - it's probably obvious (although it wasn't to me 8 years ago) but a small business can drown in quality and support issues if it isn't properly organised.