Facebook's beta WANT IT button is on hold on account of a legal challenge by some small company I've never heard of that claims rights to WANT IT. Good luck.
Ebay's knock-off of the Pinterest format is widely panned.
People at Etsy are starting to complain that Pinterest traffic is scant and barely converts: [pinterest-out.blogspot.com...] and [etsy.com...]
The self-appointed Pinterest gurus urging everyone to jump on the Pinterest gravy train are soon going to find themselves out of a job when their clients realize the so-called gravy runs too thin to make it worth one's time.
With thousands of Pinterest knock-offs out there (some successful), and big-time would-be imitators like FB & Ebay, how long until people have it up the wazoo with lined-up pictures everywhere they go?
The reason so many are copying Pinterest is that the fastest way to accumulate content is by providing a crowdscraping platform. That's quite seductive for lazy webmasters.