Cost per click, often called CPC, means the amount paid each time someone clicks an advertisement. If an ad platform charges fifty cents per click, every visitor from that ad costs fifty cents. In affiliate marketing, profit depends on whether those visitors buy the promoted product. For example, paying ten dollars for twenty clicks may be fine if one sale earns twenty dollars commission. When clicks are expensive and sales are low profit disappears quickly. Watching CPC carefully protects advertising budget. What opinions exist about managing CPC?