ADI - MozillaWiki

ADI stands for "Active Daily Installations." ("ADU" or "Active Daily Users" is sometimes used to refer to the same number.) Mozilla measures Firefox usage by the number of Firefox installations that retrieve blocklist updates from Mozilla's servers each day. This measures the number of computers running Firefox that day (excluding any that have the blocklist disabled or cannot connect to the updat

[Rockridge]

ADIはActive Daily Installationsの略で、Firefoxでいえばblocklistのアップデートを受け取った数を基準とする。一人のユーザーが複数インストールしている場合は常用ユーザー数（ADU）とずれるが、MozillaはADIで統一するようだ。