We all know that 'word of mouth' and 'word of mouse' works well, and the key is doing 'stuff' that gets people talking about you (in a positive way, of course!). However, it's worth pointing out that the challenge for all of us is to 'keep the conversation' going.
You might have done a brilliant job for someone six months ago, even 3 months ago, but many of us have short memories. Your challenge is not just to keep doing stuff, but letting people know that you're still doing it. Even better, that you're doing new stuff too!
How much of your 'marketing' efforts are spent on reinforcing and reintroducing your 'dramatic difference'? And no, I don't mean your adverts, brochures and mailshots that simply 'push' your products and services on customers, but 'real examples', things that get customers to 'notice', and crucially tell others.