Why are generic domains valuable?

Single-word-Generic domains are probably the most valuable domains of all. These domains are usually nouns, and they ARE NOT BRANDS or TRADEMARKS. In fact, most of them can't be trademarked because their common words -- which is why they're called generics.

I think what makes them valuable is that: 1. They are memorable 2. They may be typed-in by users 3. They could create traffic for many companies, but they only work for the owner.

If you don't believe me, Here is an interesting list of big companies that own generic domain names (copied the first few):

• Bank Of America - Loans.com
• Barnes and Noble - Books.com
• Bayer - Aspirin.com
• Carl's Jr - Burgers.com
• Citibank - StudentLoan.com
• CityBreak - Visit.com
• CNET - News.com TV.com
• CNN - Money.com
• CondeNast Publications - Gourmet.com
• Diago - Malts.com Rum.com Scotch.com
• Disney - Movies.com
• More...