Barack Obama signs up to Pinterest Announced yesterday via President Obama's Twitter account, the US leader is now sharing his collection of politically themed images and recipes. "Organizers, infographics, murals, and cake - now pinning all of the above for #Obama2012 on Pinterest," the account tweeted. Pinterest's populatiry has soared in recent weeks, with the latest comScore figures showing it is attracting 17.8 million unique visitors a month. The 30-person start-up based in Palo Alto, California, is very popular amongst American women internet users. In the US, 83 per cent of Pinterest's US users are female - whereas in Britain, according to figures from Compete, Pinterest's membership is 56 per cent male. The average US user is aged 35-44, while the average British user is 10 years younger. Pinterest's user base is overwhelmingly American though, with around 12 million members, compared to 200,000 in the Britain. One way that Pinterest already makes money is by converting pins into affiliate links with ecommerce sites. That means that if you post a picture of a sofa that you are thinking of buying, Pinterest could add an affiliate link to a partner retailer so that the site gets a cut of any subsequent purchase. The site's Q&A says "We might also try adding advertisements, but we haven't done this yet." Other ways that the site could make money in the future include selling additional tools and features for brands or high-end users or charging for 'sponsored pins'. Membership to Pinterest is invite-only at the moment so you will have to know someone who is a member or request an invite from Pinterest and then wait a day or two.