>I agree with you
>
> But I see many website that does not offer a demo
> I wander why they work that way
One reason may be related to the additional work of creating a demo version. As you can see in my other reply, it should be relatively simple to create a demo for VFP.
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)