Gas is sold from soda, water, or beer bottles in most of the world.
The above photo from Sihanoukvilla, Cambodia shows how gas is commercially distributed in most of the world. Outside of expressways or the fashionable, wealthy areas of capital cities, gas for personal cars, motorbikes, and tuk-tuks is often obtained from little wooden stalls set up in the street in front of homes or small shops. These are places that don’t have gas pumps, and essentially don’t have any real need for them.
Gas is sold by the liter in most countries, and these impromptu gas stations simply measure it out in soda, water, or beer bottles. There is no confusion over volumes — everyone knows how large a bottle of Coca-Cola is. A customer simply pays for however many bottles they want, and the attendant pours it into their tank.
This is a simple way of doing something that is, ultimately, simple.
The following photos are of a gas stall in Jakarta.