Click-to-buy buttons are the must-have accessories for big digital platforms. Facebook and Twitter both have them. Instagram just got one today, and Google's is on the way. Not to have one is quickly becoming very 2013. 

But don't make the mistake of thinking Pinterest's 'Buy' button, also announced Tuesday, is a me-too move. That's because commerce is likely to be a much bigger and more central activity on Pinterest than on any of those other networks -- so much bigger, that $11 billion valuation may start to seem like a tight fit before long.

"For me, a 'Buy' button makes way more sense for Pinterest than it does for some of those other social platforms," says Debra Aho Williamson, principal analyst at eMarketer. "It just feels more natural." 

To understand why, think about the mode people are in when they use Pinterest. A primarily visual social network and search tool, its 47 million U.S. users treat it largely as as place for gathering ideas for projects and plans, from recipes to vacations to home renovations. The vast majority of these projects involve spending money. You can't say the same about reading breaking news on Twitter or looking through a friend's baby photos on Facebook. 

Pinning something "is a very natural prelude to buying something," says Williamson. "If you pin it, that means you like it, which means you might buy it sometime." 

Pinterest users are already buying the things they see there, of course, and 80 percent of htem are even doing it through their phones. The button is just a way of ensuring that Pinterest gets a cut of the action. For users, the benefit is an easier purchase process, CEO Ben Silbermann said at a launch event at the company's San Francisco offices. "Right now, even though everyone uses their phones for just about everything in their life, it's still a pain in the neck to buy things," he said. "We don't want pinners to have to go through that."  

Published on: Jun 2, 2015