Investors are starting to realize what Google, Amazon and eBay have clearly been thinking about: It’s been very hard for small businesses to market themselves online. While clunky Yellow Pages and classified newspaper ads are old news, nothing has really taken local merchant ads to the next level. Small businesses can advertise on Google, but it’s much harder to proactively reach new customers than in the day and age when everyone subscribed to a local paper. Companies like these three small-caps, along with Groupon and Livingsocial, allow small businesses to better represent themselves in the digital landscape.