A mug is testing retailers’ ability to juggle inventory and turn a profit as shopping increasingly moves online. This specific travel mug is made by Yeti Coolers LLC, a small, nine year old Austin company known mostly for its $400 coolers that promise to keep things cold for days. The cup has been one of the best-selling items at outdoor and sports retailers during the holidays. It appeals to shoppers because it keeps drinks cold or hot for long stretches and is a way for consumers to grab some of the Yeti prestige without spending big bucks, retailers say. The problem is Yeti didn’t make enough mugs. That has left retailers such as Cabela’s Inc. and West Marine, scrambling. It also is testing retailers’ ability to juggle inventory and turn a profit in an era when more shopping is moving online, a trend that has accelerated this holiday shopping season. Read more at The Wall Street Journal.