Trust is what that matters the most.
Does your customer trust you? If not, forget anything else, this this first thing you should do. You have to make your customers realize that why they should trust you. Even if your product/services have some flaws, make your customers realize that you are always there for them, to help them, to listen to them, to serve their needs.Are you marketing your product by enumerating the best features and functions it provides, Nah! it takes more than that to build customers' trust.
OK, let me ask you a question. Who are the people that we actually trust? If we think a bit, we trust our family, close friends, close relatives and the person/brand who is trusted by large community.
Family and friends are fine, but the important question for an Entrepreneur arises here is - How to become a person/brand that is trusted by large community?
Customer's service 24x7
There may be many theories but the secret is simple.
"Make few people trust on you and your product and then apply Recursion"
Note : Trusted customers grow customers
Once your customers starts building other customers, you can move as fast as you can, but I recommend to be slow at initial stages. Why? Let's discuss some consequences and negative sides of it.
If your trust cycle is broken in a small community you can manage it but if it is broken in large community, it will exponentially grow the negative effect. Building trust takes time but it takes a second to break trust. Your customers' trust may be broken by various reasons, may be you dint treated them well, dint listened to them, when they needed you the most you ignored them, and believe this too - Breaking trust will grow a negative image of you and your products/services that you dint even have and it will grow like a nuclear reaction.
Remember, being an Entrepreneur, don't think that you have to work for your product and your Enterprise. Instead, think that you have to work for the customers, keep earning their trust and help them in providing an ecosystem just made for them.