http://webhosting.info/webhosts/ctoplist/US

Wildwestdomains.com 1,664,118
Register.com 1,517,071
Networksolutions.com 1,444,011
Enom.com 1,185,727
Yahoo.com 598,058
Directnic.com 455,156
Verio.com 419,112
Mydomain.com 354,485
Buydomains.com 314,828
Dotster.com 282,579

BuyDomains is huge :)

Most of the *statistics* at webhosting.info are way off base. I certainly wouldn't draw any conclusions based on anything I found there....

I suprised at yahoo.com's numbers. They host a good number of domains

Top 20 by Host Name

The top 20 name servers ranked according to the number of domains handled by each name server, with a name server uniquely identified by its fully qualifed name, are shown below.

Name Server Name Name Server IP Domains
ns.buydomains.com 208.254.3.177 109,694
this-domain-for-sale.com 128.121.3.72 109,684
dns1.name-services.com 63.251.163.102 89,998
dns2.name-services.com 216.52.184.230 89,996
dns3.name-services.com 63.251.83.36 89,975
dns4.name-services.com 64.74.96.226 89,948
dns5.name-services.com 212.118.244.163 89,582
a.ns.interland.net 64.226.28.33 50,959
b.ns.interland.net 69.0.145.33 50,930
c.ns.interland.net 64.77.127.42 50,769
ns8.san.yahoo.com 66.218.71.205 44,742
ns9.san.yahoo.com 216.109.116.20 44,741
ns2.ultsearch.com 212.100.230.160 43,978
ns1.ultsearch.com 213.130.63.232 43,978
ns.schlund.de 195.20.224.97 42,404
yns1.yahoo.com 66.218.71.205 42,301
yns2.yahoo.com 216.109.116.20 42,301
ns1.secure.net 192.220.124.10 42,260
ns2.secure.net 192.220.125.10 42,252
ns1.directnic.com 206.251.177.2 39,176