There was a time in the not-so-distant past, when many retail products - particularly encyclopedias - were sold by salesmen who knocked on the doors of homes to demonstrate and sell their wares.
Just like the buggy whip and the hurricane lantern have almost disappeared with the onslaught of industrial and technological progress, so has the profession of door-to-door selling.
A few years ago, Forbes magazine had listed '10 Top Dead or Dying Career Paths'. Telemarketing and door-to-door selling was 7th on the list - just ahead of photo film processing.
Before the advent of the Internet and social media, the only way smaller manufacturers or dealers could mass-market their products was through door-to-door selling.
Salesmen were paid a token salary - or none at all - and made money through sales commissions only if they met their monthly or quarterly targets. Each salesman was allocated a specified locality or territory - where they had to compete with other salesmen selling similar or different products.
Home owners were bothered and irritated by their door bells being rung by salesmen at all odd hours trying to sell them anything from incense sticks and toothpaste to books and vacuum cleaners.
Most slammed the door shut on the faces of the salesmen. A few who were kind enough to listen to a salesman's pitch probably didn't buy, giving some excuse like "I just bought a similar product" or "I don't have enough cash with me."
In other words, making a sale itself was a difficult task. Meeting stiff monthly sales quotas was nearly impossible. Still, the salesmen would go on their rounds come rain or shine - knocking on doors and getting them slammed in their faces.
You can just imagine the kind of resilience and discipline that was required to carry on - despite knowing that the chances of success were negligible. But when they did make a sale, good salesmen ensured that they sold their higher-valued products so that they could earn more commission.
Being able to handle repeated disappointments and having the mental wherewithal to bounce back and keep trying is just the kind of discipline one requires for success in the stock market.
A successful salesman eventually developed a winning strategy after repeated failures. So should a stock investor.
If you have tasted some success by buying a stock without doing much research and then selling it at a profit, you are unlikely to be able to repeat your success.
Even after doing proper study of a company's annual report and its stock price chart, the stock you pick may not give you the returns you expect.
Eventually, the resilient and disciplined investors will learn from their mistakes (or follow the advice of an experienced investor) and learn to follow a plan and a strategy that enable them to select winning stocks.
And once they have picked a winner, they buy a lot of it and hold on for the long-term to reap the benefits of dividends, rights, bonuses and buybacks.