I'd argue that the difference between iPad, iPad, MacBook Pro and Qwickster is that it's very very easy to mis-spell Qwickster.
It could be Qwickster, Quickster, Qwikster, Quikster, Qwickstr (if you wanna go the Flickr route) and probably some variations I haven't thought of. At the very least, Netflix should have made an effort to secure the domain-names for these alternate spellings to ensure their customers can find them when they finally go live.
The other difference is that Qwikster is a deeply stupid name.
The other other difference is that iPad, iPod, iPhone, etc. actually describe their eponymous products, and Qwikster doesn't recognizably describe anything.
Huh? The iPad is pad-shaped and "pad" is a commonly-understood noun in the tech world to refer to these devices.
Same thing for iPod. It's pod-shaped (or was when it was introduced) and it's a pretty simple mental leap to classify this "pod" as a thing that you put your music "into".
By stark contrast, "Qwikster" has absolutely no mental, cultural or conceptual link to the product or service it describes. It's worthless as a name in addition to being confusing, already taken by various other services, impossible to spell, and dorky.
Oh I'm sure I could rattle off at least a hundred or so names of products and services that have no relationship to their relative products, are challenging to spell (assuming you hadn't heard of them before) and sound somewhat similar to other services.
It could be Qwickster, Quickster, Qwikster, Quikster, Qwickstr (if you wanna go the Flickr route) and probably some variations I haven't thought of. At the very least, Netflix should have made an effort to secure the domain-names for these alternate spellings to ensure their customers can find them when they finally go live.