How to get clients for your just-started outsourced product development startup?

2 of us are planning to start a outsourced product development firm. We will deal with developing custom web applications from the ground up. We have very good expertise in the entire Web stack in PHP and Python. Recently, we made a learning platform for a US client who will be launching the product within a week in India. In the learning platform, teachers can make courses - upload videos to S3, add quizzes, add lessons etc and students can login and take the courses. Various analytics will be collected on the users activities like time watched in a video, quiz performance etc.

It was a big project which took us 1.5 months end-to-end from the server part to email framework in SES to S3 management framework. We are happy to see the final result here.

I want to ask how to keep getting such kinds of projects - we are not interested in doing a small work of a week or so but a complete solution like we did in this case. I tried Elance but good projects are very less and the hit rate is pretty bad as we have nothing to show there.

I am looking to hear from you guys as I am sure many of you must have made successful businesses in this model. Any general ideas / advice will also be most welcome.

Thanks.