Ah yes, time to for final M in our Market, Message, and Media foundation. To recap:
I cannot stress enough how important this process is. With a full list of targeted media channels (try to get at least 10), you can then determine, based on price and expected return, which ones to try out first. Some will work, others will need to be tweaked, and some will get dropped completely. The point is that you have a targeted segment, a compelling message, and appropriate channels to test and measure. Once you start measuring your marketing, you regain control your budget, your growth, and your cash flow. For example, look at the sample data I put in the graph above. When I contact a media channel, I always want to know what the average views, clicks, visitors (anything) a typical campaign can bring in. They might not give you a straight answer and say "well that depends on ....", but get a typical, or average, response they've seen with a similar ad in the past three months. They will have that information on file. Knowing this limits the risk of your investment and sets up a better expectation for you (and your marketing dollars) and the results you can expect. As always, if it's measured, then you'll know for sure how the spend/marketing channel went. Finding a profitable marketing channel might be challenging at first, but it's not impossible, and certainly obtainable if you set up the three "M's" marketing foundation as early as possible! 
- Market is the "Who You Will Serve"
- Message is "What You Will Say"
- Media is "Where You Will Market"