A simple analysis:
Backlinks: (according to google)
Yahoo: 978,000
Altavista: 61,600
Microsoft: 153,000
CNN: 157,000
Amazon: 2,610,000
Adobe: 77,900
...
Google: 3,750,000
Number of Citations: (according to google)
Citation:
Yahoo: 365,000,000
Altavista: 13,800,000
Microsoft: 627,000,000
CNN: 68,300,000
Amazon: 242,000,000
Adobe: 430,000,000
...
Google: 662,000,000
Allinurl:www
Yahoo
Altavista
Microsoft
CNN
Amazon
Adobe
Allinanchor:www
Yahoo
microsoft
cnn
amazon
adobe
allintxt:www
xe
opera
barnesandnoble
ssa
Tentative Conclusion: keywords in anchor text and in urls rule, IMHO!