opt-in

基本解释

This means more retailers are sending at least one email in the crucial first 30 days after opt-in.
這就意味著越來越多的零售商在客戶選擇性加入後的至關重要的30天內至少會發出一封郵件。
In this application, the system first sends out an opt-in request notification to users it finds, asking for their communication data upload.
在此應用程序中，系統首先曏找到的用戶發送 opt-in 請求通知，請他們上傳通訊數據。
Latitude is a similar opt-in service to My Location, except it allows you to share locations between friends based on your mobile phone or desktop location.
是一個與我的位置相似的服務，衹不過它是允許你在你的朋友間分享你基於移動電話或者桌麪電腦的位置。

Hopefully, if you opt-in for this tablet, you can live with that permanent application load.
ENGADGET: Samsung Galaxy Tab 2 7.0 review
"Opt-in is really the most burdensome privacy restriction that we implement in the U.S., " Zanneis says.
FORBES
After a few weeks, YesMail agreed to the stricter double opt-in rule and dropped its suit.
FORBES: Spam Warfare