In the first 15 seconds, your visitors are lazy in the sense that they have no extra time to invest in something they don’t know. They are vain in that they want to look good quickly using your product. And they’re selfish in that, despite the big picture potential and purpose of what your service stands for, they want to know what will immediately benefit them.
Pull new people through their initial skepticism and indifference with a hook. Most often, the hook is an abstraction layer of the value beneath.
This goes for everything we need people to engage with.