Every year, our sister site, Subcription Site Insider, holds an international testing awards competition to see which digital publishers and agencies are doing the best A/B and multivariate tests to increase sales, conversions, retention, and all-around effectiveness. Like previous ones, this year was no disappointment. We received some very inspiring entries, and here are the winners by category:

We were also fortunate enough to get our guest judge, FT.com's Optimization Manager Reagan Mille...