Sterno works - but it is slow compared to other stove options. My first backpacking stove was sterno and I used it to fry fish and boil noodles. The sterno setup was much cheaper for the occasional backpacker.
The cheapest setups today are Alcohol stoves. The liquid Alcohol can be burned much faster than the gelled Alcohol in Sterno. I've attached an example of a Sterno stove with a Trangia burner
to show another way of using the folding sterno stove.