Niche is key. You’ll enjoy more success focusing on specific niches than you will by, “just doing business”. Some of the more interesting sites I have worked on lately are related to the wood and lumber industry.
Altruwood is probably the most interesting. They specifically sell Reclaimed Lumber, distributing it all over the country. Reclaimed wood was originally harvested from old growth forests. Some reclaimed wood unused logs that sank into rivers and lakes on their way to the mill from harvesting operations over a century ago. This lumber can also come in the form of planks salvaged from demolished structures and remilled for resale.
You can get redwood, cedar, pine, oak, as well as veries exotic species, all with environmental friendliness and time tested strength. Reclaimed (or recycled) wood usually comes with a backstory that distributors such as Altruwood would be happy to tell you. Imagine walking on your new wood floors, made from recycled wood. What you are standing on is very much a part of history.
In line with this, another interesting avenue I am thoroughly fascinated with this website that sells Cedar Gable Vents. This is such a specific focused product, one can only assume that it does quite brisk business. Expansion is a possibility, as you could use other nice woods for building gable vents, which have a far more rich look than say, plastic or aluminium vents.
Businesses such as this are designed to thrive and survive, because although the demand for the services and products it provides are low, often competition and barriers to entry are lower to. I look forward to seeing them survive for years to come.