米国だとこんな感じらしいです。いわゆるポータル系が殆どみたいですね。日本では同様の調査ってやってるのかな？
| Rank | Web Property | % Reach | Unique Visitors |
|---|---|---|---|
| 1 | AOL Web Sites | 54.5 | 56,781 |
| 2 | Microsoft Sites | 48.4 | 27,478 |
| 3 | Yahoo Sites | 48.2 | 27,381 |
| 4 | Lycos | 46.5 | 26,380 |
| 5 | Geocities.com | 33.4 | 18,977 |
| 6 | Netscape Sites | 30.9 | 17,548 |
| 7 | Excite Network | 29.2 | 16,570 |
| 8 | Disney Online | 23.9 | 13,567 |
| 9 | Infoseek | 22.1 | 12,547 |
| 10 | Bluemountainarts | 21.7 | 12,315 |
| 11 | Time Warner Online | 20.3 | 12,315 |
| 12 | Altavista Search | 19.8 | 11,217 |
| 13 | Xoom | 18.9 | 10,723 |
| 14 | Amazon.com | 16.1 | 9,134 |
| 15 | RealSite Portfolio | 14.3 | 8,134 |
| 16 | ZDNet Sites | 12.6 | 7,146 |
| 17 | BroadCast.com | 12 | 6,820 |
| 18 | CNET | 11.4 | 6,458 |
| 19 | Infospace Impressions | 10 | 5,657 |
| 20 | eBay | 9.9 | 5,631 |
| 21 | LookSmart | 9.6 | 5,437 |
| 22 | Snap.com | 9.5 | 5,386 |
| 23 | Weather Channel | 8.5 | 4,805 |
| 24 | Barnes & Noble | 8.3 | 4,692 |
| 25 | Go2Net Network | 8.1 | 4,587 |
参考リンク：CyberAtlas: Traffic Patterns: Top 25 Web Sites and Properties | December 1998