Note: This is a problem that I began working on in 2017 (Padstash). We eventually shut the startup down because when we crunched the numbers, we saw the business model would only work at a tremendous scale. Because I was only interested in bootstrapping at the time, we knew it was a bad fit for us. Neighbor started at a similar time as Padstash and has continued to make peer-to-peer storage possible. They just raised a $10M round from top VCs in the Bay Area, so kudos to the team!
This is a two-sided problem. People have extra space in their homes, many of whom would love to pay a little less on their mortgage. The other side is that people need extra space to store things. The rise of storage units is proof of this.
An online marketplace that allows sellers to list space and buyers to find cheaper and more convenient storage. The company takes a cut of each transaction and provides security for both the seller and buyer. The only way this business model works is with a significant amount of transactions.
A college student is leaving for an internship. They need a place to keep their belongings for three months while they are out of town. They could buy a storage unit, or they could pay a neighbor to keep their belongings in their basement.