Keyzio, a real estate marketplace for buyers and sellers to connect well before it's time for either to move, wants to bring more homes on the market by expanding a typical transaction's timeline. Using the Kansas City-based startup's platform, which launched as an iPhone app in January and on the Web in April, prospective buyers can tag any home they see on a Google map on the site and either contact homeowners through the system if they're on it or send them a free postcard to initiate contact on the platform from Keyzio if they're not. Keyzio's co-founder and CEO Parker Hills wanted an easy way for potential homebuyers to reach out to homeowners, particularly in highly desirable neighborhoods with low turnover and lower inventory, to say something like, "I like your house. When y...