Why does so much product placement not have an obvious brand name displayed (details)?

I often see products in tv where I know what they are, but there’s no label marking them as such. The inspiring products were several adult toys by the designer Lelo, which do not have a clear label unless you look really closely at them in person. Which confuses me – isn’t the point of product placement to get people who don’t already buy a product to buy it? The only way you’d know most of these things is if you’re already a fan, and don’t need product placement to be interested. Doesn’t this tactic make the product placement useless?