Ads on Pinterest--Expected or Opportunity to Innovate?

On Friday, September 20, Pinterest announced that it is going to start running ads. It did so via an email from founder and CEO Ben Silbermann to its registered community saying that Pinterest was going to start carefully experimenting with ads to generate revenue for the brand. Here is an excerpt:
“While we haven't figured out all the details, I can say that promoted pins will be:

• Tasteful—No flashy banners or pop-up ads. 
• Transparent—We’ll always let you know if someone paid for what you see, or where you see it. 
• Relevant—These pins should be about stuff you're actually interested in, like a delicious recipe, or a jacket that's your style. 
• Improved based on your feedback—Keep letting us know what you think, and we'll keep working to make things better.

For our first test, we'll promote a few pins in search results and category feeds. For example, a pin for a Darth Vader outfit from a costume shop might be promoted in a search for “halloween.” Nobody's paying for anything yet—we want to see how things go and, more than anything, hear what you think.”

A follow-up to the announcement appeared in TechCrunch, where Josh Constine opined that either traffic was down or that mobile was becoming a more powerful delivery platform than desktop.  A company spokesperson confirmed the latter for TechCrunch:

"The world is going mobile and we're excited about that trend. Traffic continues to grow, breaking records consistently month over month and week over week. Mobile usage became the majority of traffic last summer and continues to grow in absolute numbers and as a percentage of traffic, which may account for third party discrepancies in measurement." 

 It will be interesting to see which mobile ad model Pinterest tests with the advertisers it has selected for the testing period and which model or models stick. Will it go the Facebook route with ads in feeds and no differentiation between desktop and mobile users or the Twitter route adding promoted pins? Will ads scroll along the bottom of the screen offering something related to the pins you’re viewing? Will the model be cost per click (CPC) or cost per impression (CPM)? Or will they discover something entirely new based on the interests and support of the pinners who love them?

“Something new” would be the most interesting, of course. From the responses I’ve seen, pinners seem to understand that Pinterest needs to make money in order to keep the platform growing and useful to them. There will always be complaints about change, and those will get attention, but really, I think most people understand that social networks start out free to gather audience and then at some point need to monetize or die. And as Debra Borchardt points out for The Street, the investors need to feel the money coming and this looks like a move towards IPO. So wouldn’t it be cool if Pinterest continues to pioneer in the community spirit and actively involves its community in voting through to the advertising model it decides to push forward with, a la the fourth bullet point in Ben Silbermann’s email?

As a pinner, I’d really like that. As a marketer, I like it even better.