<p>Even in an age of Twitter posts and Instagram photos, e-mail is still the way marketers reach the hearts and wallets of consumers. And that is why retailers are up in arms about Google's latest tweak to Gmail.</p><p>Over the summer, the Internet behemoth gradually introduced a new in-box with an assortment of folders for different types of messages, including a main in-box and ones for social networking alerts, e-commerce promotions, updates from businesses like banks and mailing-list messages.</p><p>For Google, it's another moneymaking avenue (note the ads that look like e-mails that now appear at the top of the promotions folder). Also, the company says it wants to fix e-mail overload.</p><p>Yet any tiny change that the Internet giant makes has cascading effects for businesses across the Web.</p><p><a href="http://www.nytimes.com/2013/09/16/technology/for-retailers-new-gmail-has-one-tab-too-many.html?pagewanted=all">Keep reading...</a></p><p>Read also:</p><p><a href="http://www.marketingprofs.com/charts/2013/11634/how-gmails-new-tabs-feature-is-affecting-consumer-behavior">How Gmail&#039;s New Tabs Feature Is Affecting Consumer Behavior</a> (MarketingProfs.com (subscription))</p><p><a href="http://www.brafton.com/news/email-content-counts-more-now-than-ever-thanks-gmail">Email content counts more now than ever (Thanks, Gmail)</a> (Brafton)</p><p><a href="http://www.geeky-gadgets.com/retailers-upset-over-gmail-tweak-15-09-2013/">Retailers Upset Over Gmail Tweak</a> (Geeky gadgets)</p><p>Explore: <a href="http://news.google.com/news/more?ncl=dIq9D2xTkUSUkNMBz5IhusLs4cXtM&ned=us">6 additional articles.</a></p>