CPC (cost per click)

CPC is spend divided by clicks. In an auction it is an output rather than a price you set: what you actually control is a bid and the relevance of your ad, and the platform resolves those against everyone else competing for the same impression. Two advertisers bidding identically can pay materially different CPCs because one is more relevant to the query.

CPC is the hinge between budget planning and funnel arithmetic. Clicks equal orders divided by conversion rate, and budget equals clicks multiplied by CPC. A business needing 500 orders at a 2% conversion rate needs 25,000 clicks, and at $1.60 that is a $40,000 budget. Change any term and the budget follows.

Which is exactly why chasing lower CPCs directly is usually the weakest lever available. Cheaper clicks are typically cheaper because they are worse. Suppose you cut CPC from $1.60 to $1.20 by broadening into looser queries, and conversion rate falls from 2% to 1.3%. Cost per order was $80 and is now $92. The CPC line improved by 25% and the business got 15% worse, which is the kind of result that survives in a report because the metric that moved was the one being watched.

The durable way to lower CPC is to earn it. On Google, relevance discounts your cost per click through ad rank, so improving expected click-through rate, ad relevance, and landing page experience reduces CPC as a by-product. Tighter query control does the same by removing the expensive, poorly matched auctions you were never going to win profitably. Both routes lower CPC while holding or improving conversion rate, which is the difference between a cheaper click and a cheaper customer.

Never compare CPCs across platforms or intent tiers. A $15 LinkedIn click reaching a named job title at a target account and a $1.40 Google Shopping click from someone typing a product name are not competing prices for the same thing. Both can be fair. The comparison that means something is an ad against its own history, or against its siblings in the same auction context.

One structural note for scaling accounts: CPC tends to rise as you expand, because the cheapest qualified inventory is consumed first and additional volume comes from more contested auctions. A rising CPC during deliberate expansion is the price of the expansion, and the question is whether cost per order still clears your allowable figure, not whether the click got more expensive.