While viewing http://lovelypackage.com/ which is a  great site about product packaging, it reminded me that visual design for websites is similar to product packaging. Both product packaging and the visual design layer of website design are the first thing that consumers notice when presented a product and they are key to brand identification.

Packaging such as the one liter water bottle that has its own cup (http://lovelypackage.com/1litre-water/) are excellent examples of great packaging design where the packaging is a product too (the main product in the link being water while the supplementary product is the cup.) Cosmetic products such as eye colors, have an eye line brush combined with the cap on the bottle that the main eye coloring liquid is packaged in.

In the case of websites and online services, the visual design of an online service plays the same role as the packaging of a physical product where its critical function to capture a passer by's interest visually by creating attractive artwork while at the same time providing visual cues about what the product is. The text on the packaging of a product and front page of a website captures the reader's (passerby's who have successfully noticed the product) attention by presenting the user with available product features that they would most likely be interested in.

It can be argued that most if not all online products/services have the working product combined with its packaging. The databaselayer, the programming/API layer,  the interaction layer and the presentation layer are all combined together to form an online product/service. Software that can be purchased on CD (or in the old days, floppy disks) can have the packaging separate from the actual product.

There are physical products (usually electronic) where the interaction layer can be separated from the main product. For example the remote control of a TV, the latest ipod shuffle (the body of the shuffle has no controls and an ipod user relies on buttons on their ipod shuffle headphones to control the ipod) and most video game console products have the interaction/controlling mechanism of the product separated from the main product that a consumer purchases. In many cases, the interaction/controlling mechanism can be purchased separately from third party manufacturers as well. The third party products can also provide ways to interact with the product that are not available on the main product manufacturer's controller. An example could be a wheel (similar to a mouse wheel) on a TV remote controller instead of only buttons to control the volume or switch back and forth between TV channels.

Online services such as twitter work along similar lines (seperating the interaction client/device from the host service/device) where the controlling service can be seperated from the main program/product/service.The Twitter website is the main messaging service with its own interaction system but external clients can also be used to interact with the main service. The twitter website stores messages in its database while providing an API  that its own website or a third party service can use to store or retrieve messages in twitter's database.

 While the features on twitters on website can be duplicated by external clients, the layout of the features on the external client can be unique to that client. Sometimes the client can combine features from another website with an API (eg. facebook, flickr) along with the twitter features on a single client in the way tht tweetdeck allows posting messages to both facebook and twitter (similar to how a remote control can control TV sets from different manufacturers.)