The news that Pinterest is testing an advertising play is sure to have Facebook and Twitter on pins and needles due to the upstart?s more innate orientation towards commerce.

With the number of social media users growing rapidly as well as the amount of time spent on these sites, Pinterest is the latest to consider how to sell advertising against its user base. Mobile advertising will play a key role in Pinterest?s strategy ? as it does for Facebook and Twitter ? since this is the fastest growing area of use.

?While it will take some time to build a track record, I do believe this move is significant to the mobile advertising space,? said Matt Murphy, CEO of Fusion92, Arlington Heights, Il.

?The major difference between Pinterest and most other social media properties is the fact that their users are typically closer to making a purchase decision,? he said. ?Pinterest users are either posting things that they like or want or are surfing Pinterest for ideas.

?This makes the Pinterest audience more receptive to advertising because they are already in a shopping mentality. If done well, I do believe Pinterest will capture a significant portion of brands digital media spend.

Pretty pictures
Pinterest has been on a quick growth trajectory over the past few years but is still significantly smaller than either Twitter or Facebook. Pinterest placed No. 49 in comScore's list of the top 50 U.S. Web properties for July of this year with approximately 25 million visitors compared to 142 million for Facebook and 36 million for Twitter.

Numbers are not available for Pinterest?s mobile user base, although mobile reportedly makes up the majority of traffic and continues to grow.

While Pinterest may not have as many users, it is significantly different from either Facebook or Twitter in that its focus is so squarely on images, including of the clothing, furniture and other items that users want or find inspirational.

This means Pinterest is already part of the buying process for a growing number of consumers and makes advertising that much more of a natural fit.

?Pinterest is gradually becoming the top social network where consumers go first to discover new products,? said Sharad Verma, CEO of Piqora, San Mateo, CA. ?What Google did for search via Adwords, Pinterest has the opportunity to do that on visual, discovery Web by creating a marketplace around discovery ads.

?Pinterest is uniquely positioned for this advertising model as it's fast emerging as a huge traffic driver to ecommerce sites and other smaller social/ecommerce networks like Wanelo,? he said.

?Coupled with the fact that it's a social network immersed with future and latent purchase intent, ecommerce advertisers will adopt the marketplace hand over fist to get in front of consumers who have demonstrated intent in the past.?

Real estate
Pinterest said last week that it plans to test ads in search results and category feeds, enabling marketers to pay to promote their pins to a wider audience.

Pinterest will face several challenges on the advertising front, especially as it relates to mobile.

Because the content is image based, adding in display ads will take up what precious little real estate already exists on a smartphone screen.

This means Pinterest will need to learn how to balance the needs of users with those of advertisers with an eye toward providing the best possible user experience.

?The challenge with mobile social advertising often comes down to real estate. Users will demand a balance between sponsored and unsponsored content,? said Deborah Hanamura, director of marketing at Metia, Kirkland, WA.

?The tolerance for sponsored content will be higher if Pinterest provides clear guidelines to advertisers regarding what is platform-appropriate, and advertisers consider the entire customer experience when they produce their ad content,? she said.

Content strategies
One example of what advertising on Pinterest might look like would be a retailer such as Nordstrom promoting its pins to all the followers of a competitor such as Neiman Marcus.

Another example would be if a retailer such as Gap promoted a certain board to all pinners who have pinned winter coats from Gap or any retailer in the recent past.

As these examples suggest, advertising on Pinterest may make the most sense for brands that have a strong content strategy.

?Brands with great organic publishing strategies will see a huge boost in their earned media from this spend,? Piqora?s Mr. Verma said.

?But it allows other brands who were slow in adopting Pinterest to get ahead by spending to reach the right users on Pinterest,? he said.

?Social Feeds are already full and move fast; advertising might is the way to guarantee visibility and reach. ?

Aspirational mode
Pinterest has reportedly recruited many former Facebook employees, suggesting it is taking advertising seriously.

The social network has also made it clear that it will focus on ensuring that ads are unobtrusive.

?Pinterest users operate in an aspirational mode,? said Danny Maloney, CEO and co-founder of Tailwind, Oklahoma City, OK. ?When people pin, they're often crafting a vision of what they want their life to be like - clothing they want to own, how they want to remodel their kitchen, place they'd like to visit.

?That's an ideal environment for brands to show how they can help make that vision a reality,? he said.

?Advertising on Pinterest will enable brands to enter the decision-making funnel before a purchase decision is reached.?

Final Take
Chantal Tode is associate editor on Mobile Marketer, New York