In an average years a start up business could be profitable in 2 to 3 years time. That is right if your business is not earning within 36 months you probably shut it down or if you still want to revive it you have to change your marketing plan and assess what is wrong with you current strategy why you are not able to generate profit. That it is possible that your business is not profitable in the first 3 years then it would boom on the 4th year. That is why businessmen has a high risk tolerance in creating his own business. To be able to have a profitable business you should have a lot of patience, capital, a good marketing strategy, and also you do know your specific goal, know your customer as well.
I think that was long. Maybe if the business is slow and then other things are not that great but that's better, at least the efforts are not wasted and maybe after these periods, earning will now be easy because the business is already well known to the public and they already have improved. If we want to revive a dead business, we need to change our approach as a whole and not just in the marketing side.
Even if you become successful about it but your product is still lousy, do you think the hype will stay? No, it won't. The last thing that you said which is know your customer, reminds me of KYC online lol but yes it's important and the KYC offline is different. It is knowing what their need is and then you need to be friendly about them so that they will keep on coming back.