It could be misconstrued that Netflix is endorsing it and because there is an alternative way to describe what Netflix does (i.e. Rental Service), they may be asked to change the wording. If using "Netflix" is the only way to describe the product without actually implying endorsement, than they will probably be safe. Another perspective is that you can generally use other trademarked names as long as you don't make profit from their actual names. So I can make a netflixsucks.com site and would be protected in doing so as long as I don't make a profit. Other than that, as long as they are truthful and don't confuse customers they can probably find a way to finagle using "Netflix for Baby Clothes" somewhere in their promo material.