This week, comScore put out its monthly list of the top 50 sites in the U.S. (in terms of unique visitors), and Pinterest made the list for the first time. It’s still growing. As it continues to attract more users, online retailers will continue to try and use it to their advantage and sell more items.

Have you been able to leverage Pinterest to increase your online sales? Have you ever bought something you found on Pinterest? Let us know in the comments.

We spoke with Matt Pine, VP of Marketing at Ubokia, a service, which lets shoppers post what they want and get matched up with people selling those items. “Think Craigslist in reverse, but now people looking for something don’t have to spend all day sitting behind a screen hitting the refresh button, you can post your ‘want’, and the item (seller) will find you,” explains Pine.

Ubokia specifically takes advantage of Pinterest to match buyers and sellers, so the company knows a bit about the e-commerce side of Pinterest.

“In general, I believe that Pinterest has the potential to provide the biggest evolution in ecommerce since Google launched AdWords,” Pine tells WebProNews. “Of course there are countless factors that will come into play. At it’s core though, Pinterest is the greatest ‘discovery’ engine we have ever seen. If Pinterest can develop a way to seamlessly integrate a module or process for users to actually acquire the items they discover then they can definitely become a powerhouse in the ecommerce world.”

Pinterest is already showing that it is interested in ecommerce. It already has a Gifts section, which lets you browse items by price.

“Well, Pinterest is all about pictures, so it starts with quality pictures,” says Pine, when asked about best practices for selling items through Pinterest. “Captions are underutilized on Pinterest, but are the key to showing up in Pinterest searches. Sellers need to make sure that their images link directly to a page where a person can purchase an item. For example, we have a number of jewelry sellers who list items for sale on Ubokia, then pin those items from Ubokia to Pinterest. That way an interested buyer can immediately communicate with the seller or make a purchase.”

“The difficult part of selling online is getting enough [of] the attention of enough potential buyers to convert sales,” he continues. “On Pinterest, this means that sellers need to build quality pin boards to build large followings and generate significant repins. The only way to really achieve this on Pinterest in through organic practices of pinning quality, original content. Unlike SEO, there is not really an effective way of artificially increasing one’s Pinterest following.”

“Additionally, sellers need to be proactive on Pinterest by reaching out to people who repin their content,” he adds. “All repiners and followers are potential customers and sellers need to reach out to them. Communicating on Pinterest is not that easy as the only real option is to leave comments on a user’s pin.”

Facebook is currently testing a feature that could compete directly with Pinterest, despite Facebook’s importance to Pinterest’s own growth. With the feature, retailers can provide users with the ability to “want” items, and create wishlists.

While Pine admits that he hasn’t had the chance to experiment with the feature, he says, “I believe that Facebook is on the right track for bringing social commerce into the Facebook fold with the ‘want’ concept, but giving a user the ability to state that they want something is only a small part of the equation in leading to successful transactions. Facebook will need to develop a platform that will allow sellers to find relevant buyers, then communicate with them.”

“Additionally, the platform will need a transaction module as well,” he adds. “Basically, we are talking about a complete ecommerce platform. How will Facebook handle ratings, fraud, spam, etc?”

“Building a marketplace is not something that can be built overnight from the ground up – even with Facebook’s resources,” Pine says. “Marketplaces are not built overnight. Additionally, Facebook users have historically been adverse to engaging in commerce on Facebook. So Facebook will have to develop a very well thought process for implementing commerce into the Facebook experience. In the end of the day, Facebook always has the potential to be a competitor because they are Facebook. Personally, I am really excited about this because it simply validates the ‘want’ model for commerce.”

We may soon have a better picture of the direction Facebook commerce is going in. Next month, the company will hold an event to talk more about its Gifts offering, launched in September.

Perhaps Pinterest will find a way to play into the feature.

As far as selling items via Pinterest, you’re more likely to find success in certain categories at this point.

“Jewelry, home decor, and fashion jump out as the big ones, but we are also seeing people use Pinterest and Ubokia in creative ways,” says Pine. “For example crafts are very popular on Pinterest, and we are seeing buyers who lack the creative ability, but desire to purchase the finished product posting wants from Pinterest.”

Pinterest has been expanding its categories as well, and I expect this will continue as its audience size grows.

It is worth noting that Pinterest has apparently been doing better than Facebook and Twitter, when it comes to average order value.

This week, Pinterest revealed that it is rolling out a new site verification feature. This will be important for users to establish trust, and is worth considering for ecommerce businesses.

Do you believe Pinterest will become an important tool for online businesses? Is it already? Share your thoughts.