So this is something like consulting through video calling? This should not be very expensive for customers, and not so difficult for experts to not do this

This is convenient in the event that you have a problem, and there is no way to go, or take something to the workshop. You just consult through a videoconference.
Most likely, you are right. But I can't come up with a reason why I would address the expert in this way yet.
Any question. Plumbing, repair, service, computer diagnostics, car repair, garden, cattle breeding, winemaking ...

Exactly! Our platform is primarily geared towards the long tail, and not necessarily what you would consider mainstream "consulting" like I.T., web design, SEO etc. Our definition of an Expert is someone who knows more than you on a given topic.
For example, if I am doing a DIY wood-working project and need to know how to make a certain difficult cut, I don't need the world's greatest wood-working expert to show me. Someone who has done it before can demonstrate it for me and I'll be all set and can move on with my project. I *could* go Google or search YouTube, but when you don't know what you don't know, it is sometimes hard to get the right results, and when you do have results you can't be sure if they apply to your situation.
These are the scenarios Interface has been designed to address. Today, the world wastes tons of brain power by not tapping into the expertise of retired professionals, stay-at-home parents and people living in remote locations. WhenHub Interface will help the world tap all that brain power and knowledge.