Shares of Shopify sank more than 9 percent on Tuesday. The company's CEO Tobi Lutke failed to sufficiently address concerns raised earlier this month by short-selling firm Citron Research. The firm claimed Shopify oversells the potential for profit on its platform, and accused Shopify of paying bloggers to send merchants to its site. This in spite of reporting a 72 percent jump in quarterly revenue. Ted Rubin, CMO of Brand Innovators and Co-Founder of Prevailing Path, says Shopify has a competitive advantage in the retail landscape through its software. Rubin says Shopify should stick with its strategy, because influencer marketing is becoming increasingly important.