1) Blocking by IP address. (AOL and Universities come to mind.)
2) nofollow links are followed by search engines and users alike. (display:none is ignored by some text-based browsers that ignore CSS.)
1) Blocking by IP address. (AOL and Universities come to mind.)
2) nofollow links are followed by search engines and users alike. (display:none is ignored by some text-based browsers that ignore CSS.)