每点击付费（Pay per click / PPC，也称作 Cost Per Click / CPC）是一种网络广告的收费计算形式，广泛用在搜索引擎、广告网络、以及网站或博客等网络广告平台。规则是广告主只有当用户实际上点击广告以拜访广告主的网站时，才需要支付费用。广告主可以竞标他们认定的目标市场对象在寻找某一种类的产品或者服务时，可能会在搜索时输入的关键字。当用户键入关键字查找与广告主的列表匹配、或者查看某相关内容的网页，该广告主投放的广告就会显示。该链接被称为「赞助链接」或者「赞助广告」。它通常出现于自然或者随机结果页的侧栏 (有时位于其上)、或者任何地方网管或博客主决定放于内容页的任何地方。

Pay per click (PPC), also called cost per click, is an internet advertising model used to direct traffic to websites, in which an advertiser pays a publisher (typically a website owner or a network of websites) when the ad is clicked.

Pay-per-click is commonly associated with search engines. With search engines, advertisers typically bid on keyword phrases relevant to their target market. In contrast, content sites commonly charge a fixed price per click rather than use a bidding system. PPC "display" advertisements, also known as "banner" ads, are shown on web sites with related content that have agreed to show ads and are typically not pay-per-click advertising.