An online database of ideas for various business startups that would likely succeed because an obvious unfulfilled niche exists at a certain place and a certain time. Such business ideas don't have to be novel per se or bring about some unexisting/significantly improved product or service, they only have to point to an existing business opportunity.
There's a new catching up style trend in some city but there's no shop oriented towards it, opening a shop focused exclusively on that style type would attract customers.
Car repair shops in a certain country/location don't provide the service of restoring certain parts of a car engine, therefore people having problems with those have to either buy a totally new part (which might be very expensive) or put a second-hand one with no guarantee if and for how long it will last. One could open a repair shop focused solely on restoration service.
Opening a large size vegan supermarket (in any big enough city) with a product variety and prices not significantly different from that of an ordinary supermarket.
Anyone could suggest a business idea on the platform, those would get rated according to how good/likely to succeed they are. The ratings of people from a location most relevant for a certain idea would be prioritized. People with resources and ambition to start a business could browse through such database to get inspiration. You could search for ideas according to the location in which you want to start a business, business sector, and more.
Those suggesting the ideas would mostly be people who won't do it themselves but would like to see such ideas realized, for example, potential customers (people currently in demand for some service/product) or businessmen who are too busy with other projects. Business ideas that are relevant worldwide would also be welcomed on the platform.