Great ideas and bad ideas are only great or bad in retrospect. Ideas when they are first conceived are neither, it takes implementation to decide. So, the only way to know if your marketing idea is a good one is for people to see it. Yet the majority of advertising is subjected to hours of research, focus groups and reviews before anyone see it. That’s because there is a huge amount of uncertainty and money on the line.
The book The Lean Startup explains how startup business should treat uncertainty which I think can also be applied to dealing with the uncertainty of marketing: by advocating the creation of rapid prototypes designed to test market assumptions, and using customer feedback to evolve ideas much faster than via more traditional product development practices. I think the internet makes this a possibility for today’s advertisers. Create a prototype ad and measure its effectiveness on the web to specific targets before launching it more broadly.