Any idea starts with identifying the key pain point it is going to solve and which segment of the consumers will it help. Identifying the segment of consumers is more important then the execution plan for the idea itself because, execution plan changes according to your consumer.
There are two ways to do it, either work with the existing segments or create your own market.
Take Audi, when they entered Indian market with their flagship Q7, they did not go into mass advertising.They first identified their segment of consumers – Film Starts and Influential people. Why? Because usually people aspire to be like their favorite stars and successful people. They want to use the same brands like them and they wish to be successful like them.
Audi wanted to create a niche market for themselves and so, they went door-to-door with their sales team. Over the last ~9 years, they have not only build a niche, but created a complete different market for luxury cars in India which Mercedes could not do being here for a long time.
In the recent times, I have seen Big Basket doing the same. They invested in roping in Shah Rukh Khan for their Radio ad. When SRK himself uses Big Basket, why will his fans not?
This is how you create your market. Identify whom your Product relates to and then start from the top.