Here's an old sales question for you:
Is it easier to sell one person one item for one million dollars, or to sell one million people something that costs one dollar?
It's not a trick question and the logic goes that it's much easier to sell one person something for one million dollars.
When it comes to the online world, I'd argue that it's equal. Heck, it might even be easier to sell one million people something that costs one dollar.
Business models simply don't look the same to any of us anymore (and that goes for the music industry to the marketing industry and every other industry in between), because all markets look smaller in comparison to how businesses worked and were built before.
The truth is that they're not smaller. Products seem much more targeted.
Here's the challenge: don't get sucked into the mass media mind-set when it comes to online.
If you know that you can reach your entire market of 100,000 potential customers, why would you worry about buying media on a CPM (Cost Per Thousand) basis?
Focus on your target market. Focus on delivering them relevant content. And, most importantly, focus on advertising and communicating to them where they are, instead of where everyone (in the whole world) is.
The Digital Marketing channel offers you the ability and the channel to focus.