MVPs (Minimal Viable Products) are an experimentation tool to test hypothesis. Time and money are valuable resources and MVPs enable you to mitigate the risk of building something nobody wants.
Below is a great example that caught my eye on validating ideas quickly, cheaply and easily:
Demand Validation Video
Saw this on Twitter yesterday and thought it was a genius way to validate whether people felt similar to Lain (idea owner) that accessories should be multi-purpose and used for contactless payments. The video above is a great example in Tesco supermarket of Lain testing her hypothesis.
The comments (feedback) from people on Twitter provides insight on peoples sentiment (as shown below). The Retweets validate that people want to share this great idea with others. This was similar in some respects to the Dropbox Explainer Video that enabled the company to gain funding 9 years ago.