In order to build customer trust, you have to do something like:
1/ The most important thing is your product must be good, noone will do word-of-mouth for you if your product sucks.
2/ Provide trust in 2 ways:
- Approved or authorized from experts (depend on industry) or featured in big newspaper
- Provide real customer reviews: my tips from my company is to do interview with customers and ask for real image to build more trust, or take the screenshot of your chat with customer when they give feedback or the social accounts of your customers.