Because of “Social Proof” that shows how other people feel when they use your product.
Humans like to buy things that other humans are raving about and don’t want to miss out. So, testimonials help boost sales.
Campaign/Widget is simply the # of separate  testimonial collection pages you can have.
We suggest using 1 Widget/Campaign per product or service.  If you plan to have more than 10 product/services, then get the UNLIMITED version because it’s only 10$ more.
People can record their testimonial directly using your landing page via ANY phone or Computer or Tablet!  There is no limitation to the length of video someone can upload.
They can even upload a video from phone/computer if they wish.
Anywhere.  WordPress, ClickFunnels, InstaPage, Shopify.  Pretty much where ever you can copy/paste a line of code.
You do not need to know any coding or programming language to embed it.