Have a solid new business development process and an action plan. Like any sales activity, you need a strong proposition and a tested process to present your offering to the market.

You are (sadly) no different to any other B2B biz dev client we have.
1 - research and build a database of your prospects (funded startups)
2 - make an offer to them that is compelling and they respond to your approach
3 - have a range of services that are easy to buy, demonstrate added value and encourage re-purchase
4 - rinse, repeat.

Happy to help you with our 8 Step New Business Development methodology
http://www.slideshare.net/rcaroe/cas-methodology-for-new-business-development