According Amazon's policy we can't use brand name in our keyword such as "sony", "samsung". Can I use "iPod", "PowerShot", "CyberShot" or something else in my keywords plaese?
you should be able to use product keywords , buyers would look to find products to buy with those words, so should be fair, it would rather depend on what kinda site are you working on, either a store or a product help site, but well finally it helps the product manufacturers , you are selling for them at the end of day.