# Bidding Guides


Use these guides for bidding and optimization.

### [Campaign budget optimization](https://developers.facebook.com/docs/marketing-api/bidding-and-optimization/campaign-budget-optimization)

Bid strategy is the core function you choose to control your cost efficiency. Different bid strategies can affect your bids and your cost differently.

### [Optimized cost per mille ads](https://developers.facebook.com/documentation/ads-commerce/marketing-api/bidding/guides/optimized-cost-per-mille)

Prioritize your marketing goals then automatically deliver ads towards these goals in the most effective way possible.

### [Cost per action ads](https://developers.facebook.com/documentation/ads-commerce/marketing-api/bidding/guides/cost-per-action-ads)

Specify conversion events and get charged by the amount of conversions.

### [Reach and frequency](https://developers.facebook.com/docs/marketing-api/reachandfrequency)

Bid on a predicted unique audience reach for your ads on Facebook and Instagram and control display frequency.

### [Bid multipliers](https://developers.facebook.com/documentation/ads-commerce/marketing-api/bidding-and-optimization/bid-multiplier)

Bid multipliers enable you to reduce the amount of audience segmentation required because it allows you to maintain a nuanced bidding strategy within a single ad set with one targeted audience.