The most balconies are not very spacious. They are narrow, so you want to have as much free space as possible.
On the other hand there is a growing movement for grow food by yourself.

This concept combines both aspects into one product.

Planters can be attached to the ceiling with a height adjustable jack.
So you can just pull the planters to a height that is comfortable to you.

The planters can be arranged in endless combinations - different heights, different numbers ....

Many of these planters will give the impression of a closed garden above your head.

This product fulfill the actuall need for selfgrow food, the narrow balconies, is easy to produce and can be sold as a mass market product.