A large window with indirect light is one of the best light sources you can get, and it costs nothing. Plenty of good product photography is shot on it. It also has hard limits, and brands usually discover them halfway through a catalogue.
Why window light is genuinely good
The rule in lighting is that a bigger source relative to the subject gives softer shadows. A window is enormous compared to a bottle, so it produces the soft graduated shadow that expensive softboxes are built to imitate.
It is also directional in a way that flat overhead lighting is not, which is what gives a product shape. And you can see exactly what you are getting while you set up, which shortens the learning curve more than any tutorial.
How to use it properly
Keep direct sun off the product. Direct sunlight is a small hard source and gives you black edged shadows and blown highlights. What you want is a window that light reaches indirectly, or the same window with a white curtain or a sheet of tracing paper across it.
Put the product beside the window, not facing it. Light coming from the side describes shape. Light coming from behind the camera flattens everything, which is the most common mistake.
Bounce the shadow side. A sheet of white foam board opposite the window fills the dark side. This single step is the difference between a product that looks lit and one that looks half in darkness. It costs almost nothing.
Use black card to build edges. On a glossy or white product, place black card just outside the frame on one side. It puts a dark edge down the product that separates it from a white background. Most complaints about products looking flat are solved here.
Put the camera on a tripod. Window light is dimmer than it feels, so your shutter speed will be slow. Handheld at a slow speed is soft, and soft is exactly what a marketplace zoom exposes.
The three limits
It changes. This is the one that ruins catalogues. Morning light and afternoon light are different in colour and direction. A range shot across one day does not match, and a range that does not match looks careless in the grid where buyers compare your own products against each other. If you shoot a range on window light, shoot the entire range in one short session, or accept the drift.
It is weather dependent. A cloudy day and a clear day are different setups. If a client is waiting, that is a scheduling problem you cannot solve.
It is not enough for some products. Deep focus on a large product needs a small aperture, which needs a lot of light. Window light often cannot supply it, and pushing ISO to compensate adds noise exactly where the label detail is.
Where it works and where it does not
Natural light works well for lifestyle imagery, food, anything with texture, flat lays, and small batches where consistency across a hundred products is not the point.
It works badly for pure white background listing images, which need controlled and repeatable light to hit a clean 255 white; for reflective and glass products, where you need to control precisely what the surface reflects; and for any catalogue large enough that it cannot be shot in one sitting.
The honest summary
If you are shooting a handful of lifestyle images for social, a window and a piece of foam board is a genuinely good answer and you do not need to spend anything.
If you are shooting a marketplace catalogue that has to be consistent, controlled light is not a luxury. It is the thing that makes the range look like a range. Affordable lighting kits covers what that costs, and it is less than most brands expect.