There are a variety of electric resistance heat emitters on the market.
Wall and ceiling mounted units are typically found in bathrooms.
Some electric heaters are used as toe kick heaters.
It can be useful to have a plugin electric heater available in case of a heat emergency with your primary heating system.
In-duct versions can be combined with ducted heat pumps to provide peak load heating. Ducted units can also be installed in existing hot air ducts served by oil or gas as a primary heating fuel. These can be used to offset fuel usage for people with solar who might have extra net metered credits.