Online retailers JustFab and ShoeDazzle are making a bigger-is-better play and merging in an effort to grow faster, the companies said Wednesday. "Ecommerce is all about that mass scale," said Adam Goldenberg, currently co-chief executive of JustFab. "Having that scale allows us to work with the very best factories." The combined companies should have revenue of over $400 million next year, said ShoeDazzle Chief Executive Brian Lee, and become profitable on an operating basis. ShoeDazzle focuses mainly shoes, whereas JustFab sells a broader range including shoes, accessories and apparel.