We measure the growth and performance of the Second 500 e-retailers—ones operating in North America that are ranked 501-1,000 based on 2013 online sales— for the same reason we report hundreds of metrics on each of the Top 500 web merchants: to provide e-retailers with competitive information they can use to improve their businesses. There’s as much competitive information to be gleaned in studying mid-tier players as there is in tracking the major e-retailers. In fact, the competitive secrets of the all-new 2014 Second 500 Guide may be even more compelling because they are lesser known and are often more innovative and aggressive when it comes to applying best e-retailing practices. They target market niches better than many large e-retailers and use social media more effectively as well. And because they compete for the quarter of e-commerce that is not controlled by the Top 500, they offer powerful competitive models for the hundreds of thousands of serious e-retailers who can build a profitable e-commerce business without ever making it to the Major Leagues.