Startup - One word that means many different things to different people. Some associate it with glamour, money and luxury, while others use adjectives such as innovative, disruptive and path breaking when they talk about it. Few others still think of a startup as an unnecessary risk an individual (or a group thereof) takes in the hope of winning - the odds of which are not too different from winning the lottery.

Experts say a startup is a temporary enterprise in search of a sustainable business model. They associate a startup with a huge market and exponential growth. Many entrepreneurs associate a startup with freedom. And then there are those who think of startups as unreasonable in the context of George Bernard Shaw's quote "all progress depends on the unreasonable man" and consider a startup to be the vehicle for society's progress.

For me, startups can be summed up in 3 words - Failures, Unicorns and Dark horses. Any startup that fails to implement a sustainable business model is a failure. Those that find one but can't grow exponentially are stable enterprises, but not startups. Those that find a business model that leads them on the trajectory of exponential growth become the Unicorns and startups in search of that elusive exponential business model are all dark horses.

Finding and implementing the business model that will be the engine of exponential growth is the primary challenge a startup faces. This starts with the identification of a huge market, then narrowing it down to the market the firm can reasonably hope to address in the foreseeable future, and evaluating whether the market is big enough. This is the first stumbling block.

Entrepreneurs are a passionate lot. They deeply believe that their idea is going to change the world. They firmly believe that their product services a massive market. And they put on blinkers to market realities if this belief is not validated by the market. I know this because I have been guilty of it. Unless these blinkers are removed and hard numbers are allowed to dictate the market size, the entrepreneur is only lying to himself.