The author of Zag and Brand Gap has some very strong views on what constitutes a strong name. He's of the view that a Strong name should be:
1. Differentiated. It should stand out from competitors’ names, as well as from other words in a sentence. This is sometimes called “speech-stream visibility”, the quality that lets the eye or the ear pick out the name as a proper (or capitalized) word instead of a common word.
2. Brief. Four syllables or less. More than four, and people start to abbreviate the name in ways that could be detrimental to the brand.
3. Appropriate. But not so descriptive as to sound generic. A common mistake is to choose a name that doubles as a descriptor, which will cause it to converge with other descriptive names. Actually, a strong brand name can be “blind”, meaning that it gives no clue as to its connection with the product, service, or company it represents, yet still “feels” appropriate.
4. Easy to spell. When you turn your name into a spelling contest, you introduce more confusion among customers, and make your brand difficult to access in databases that require correct spelling.
5. Satisfying to pronounce. A good name has “mouthfeel”, meaning that people like the way it sounds and are therefore more willing to use it.
6. Suitable for “brandplay.” The best names have creative “legs”—they readily lend themselves to great storytelling, graphics, PR, advertising, and other communications.
7. Legally defensible. The patent office wants to make sure that customers are not confused by sound-alike names or look-alike trademarks. A good name is one that keeps legal fees to a minimum.
He illustrates his points with some valid examples. Go here to take a peek.