I'm in the process of building an online service that is primarily focussed on businesses. I can't go in to too much detail about it, but it's a piece of software that would be used by people who deal with phone calls.
The service, as far as I'm aware of, has not been invented by anybody other than myself or available to anyone at the moment. So it's currently unique. But as it's unique, I'm not sure how to go about marketing it. How do I market this service to people who have never thought about using the service, and probably wouldn't even think of looking for it?
If no one is looking for it, then you have a tough hill to climb. You have to create the market by a) "eliciting the pain", and b) educating your prospects on the value proposition of your product.
The traditional way is to target small "submarkets". You can't just attack a huge swath of mainstream users; you have to tackle a specific region, or industry. IOW, a "vertical". You have to really put together a variant of your solution that addresses their needs with minimal disruption so that they feel safe in buying.
Three good books to spur your thinking would be "The Innovator's Dilemma ", "Crossing The Chasm ", and "The Four Steps to the Epiphany", in particular the last one.
As mentioned, creating a market is important as it apparently doesn't yet exist. One great way of doing this is by content marketing. That's a great place to bring up why your service would be useful.
Granted, content marketing must be useful to the reader and can't be a blatant ad. So instead of specifically talking about your service, you would want to talk about the industry. Topics you can focus on are why the industry is important, what problems a service like yours can solve, how it makes life easier, and why people would want to use it.
You can then distribute this content and direct the reader to your website by means of an "About the Author" box. Content marketing works, and is a great way for you to create a market.