Should monetization be an afterthought ?
Skeletor: If you have access to a research library, you could do some research and write a feasibility study in a day of work.  A feasibility study would be the first draft of your business plan after working on it for a day.Do some basic market research at the library, know how big your market (users) would be and some basic information about them (are they 13-25 WoW players or 30-45 baby booomers.)Find similar services to your idea and do some research on them.  Even if your idea is really novel, you can find replacement products and research them.
e.g.: My company is a lot like Hacker News, but for serious hard core chefs.  Hacker News make X amount of dollars with a userbase of Y users, we could probably do something similar.So spend one day of research and produce a 1-2 page document with your research.  That will really help you start to think of how to convert an idea or service into a business.  Even if you have a strong idea of how to make money on a service, knowing this basic info will help you polish your ideas and help you sound really smart when talking to investors, potential partners, and even customers.