Flash Drive Packaging provides you with more space on which to advertise, as USB sticks, or flash drives are often small, and only have space enough for a company logo or a brief message. By providing packaging, you cam increase the perceived value of what is included in the stick. This can be enhanced by the additional messaging that can  be printed onto the packaging. It may also provide protection if the stick is going to be sent through the post, or be shipped around the country from one trade show to another. It will of course increase the cost of producing the memory sticks, so this is normally a major consideration when deciding wether to use packaging or not.