Big Ideas are what everyone in advertising and marketing seems to want all the time. The bigger the better. No-one ever really defines what this means, it just has to be big, but I always think of it as something like a high-concept Hollywood film, something you can express in very few words and that everyone will "get" immediately, like "Arnold Schwarzenegger and Danny DeVito are twins".
Big Ideas are supposed to be instant, loud and obvious once you hear them. And there's nothing inherently wrong with this, except a lot of Big Ideas end up feeling more like the famous Hollywood sign: big, bright and noticeable, but with nothing behind it. They're a bit thin, a bit insubstantial. This was OK when a Big Idea only had to support three TV scripts and some print and posters, but its flatness really shows when the poor digital agency has to turn it into an extended, immersive, online experience, not just a game of whack-a-mole with the brand mascot.
Which is why, although it's just playing with words, I prefer to think about Rich Ideas. Richard Huntington describes this kind of idea as "generous" - meaning it's something that every agency and partner around the brand management table doesn't just "get", they can immediately think of a dozen great ways to bring it to life in their particular medium. A Rich Idea might have instant appeal, but it also has hidden depths, emotional resonance and inherent drama. If a Big Idea is like a high-concept movie, then a Rich Idea is like the premise for a soap opera or a series. It implies some development, some unfolding over time, some mystery. Those high-concept movies didn't spawn a load of interesting sequels because they were so thin, the cinematic equivalents of one-liners, but a simple premise such as the one for Buffy the Vampire Slayer - high-school as horror movie - conjures up an entire imaginary universe, one which its fans are still exploring. Give a good digital agency something like that to play with and it will do something magical, give it the average advertising idea and it'll do a stupid Flash game.