To answer the question "Why Pinterest is such a Big Deal all of a sudden" we will take a look into another area real quick to have a better understanding.
1. For those who don't know How Google Works and How it Ranks websites: Here is a short insight:
2. Explain that google is fighting hard against black hat techniques: Focus on negative effects of Penalties
Google renewed their algorithm and its fighting more than ever against black hat techniques. The penalties are high enough to destroy your online strategies so better don't even start with black hat techniques.
Give Examples of Black Hat techniques: Hidden Text, Source codes, links, ghost websites that are only used for linking.
3. Now Explain what Good Hat strategies are for creating links to your website.
4. So why does that have to do with Pinterest? Lets explain first what Pinterest is and does - for people who maybe don't know already.
For the user: It gives you a nice opportunity to look through interesting pictures, quotes, image tutorials, statistics, infographics aso. It's basically very entertaining.
For the one who puts up the pictures: Why would someone go through the hard work of creating all these pictures and statistics without getting anything out of it? Good question - The Answer is they get a lot out of it! As Pinterest by it's nature is very entertaining people like to look around and click through the pictures. In fact you don't only click around on the pinterest platform - as soon as you click through to a certain "Pinner" you will be automatically linked to his website. This is a very good example of a good quality link. (good hat strategy) This link in turn will be clicked by many many users which will create great traffic to the Pinners website. This high traffic will boost the websites ranking on google up in almost no-time as google understands it as good quality links.
This is the magic and the real big deal about Pinterest!