It’s the big question at OMMA’s Email Insider Summit on Friday: Is Gmail Tabs making marketers' lives better or worse? (Released by Google in May, the inbox-sorting tool removes marketing messages from users' primary inboxes, and files them in a distinct "Promotions" tab.) On a late morning panel, Dianna Dilworth, editor of MediaPost’s of Email Marketing Daily, noted that Groupon recently blamed Tabs for its poor Q3 earnings. Well, “How very convenient for them,” joked Jordan Cohen, VP of Marketing at Movable Ink. [Cue crowd laughter] “Yeah, because [Groupon’s] stock was just in great shape before that!” added Ryan Phelan, Vice President of Digital Impact Strategic Services at Acxiom. Groupon aside, “I think [Tabs is] a benefit for marketers,” said Barry Abel, Senior Vice President at Message Systems. “They’re going to learn how to use it.” But, that learning process is going to keep marketers on their toes, said Cohen. “They will have to be more creative,” he said, adding that Tabs is making matters of “timeliness and relevancy” more critical than ever. Bigger picture, “We have to take control of our channel, because others are controlling it for us,” Phelan said. “Gmail Tabs is not the problem.” Meanwhile, as a backdrop to Friday's discussion, a study released earlier this week by marketing services firm Epsilon found that Tabs is clearly causing problems for some marketers.