Create some sort of trial option
I just found this site, decided to try it out with one photo before committing, and now can't see the quality of my first clip without subscribing. WHY would I pay you at this stage? How do I know I'm not going to download some tiny, pixelated file I can't use? I'm fine with paying for a service like this, but not without somehow knowing what I'm paying for. There are lots of ways to do this: Offering at least one free clip so I can see if the quality of the final product matches my needs, letting people buy a few credits (rather than a subscription) to get a sense of the product, or letting new customers download a sample that has a giant watermark splashed over it so it's unusable but still illustrative of the product.
AdminJacob N (Admin, Clipping Magic) commented
The live preview is an accurate preview of the result, so what you see is what you get.