TikTok Ads Bidding: Lowest Cost vs Bid Cap

By default, TikTok wants to spend your Daily Budget completely. This is Lowest Cost (Auto-Bid). It is great for volume, but dangerous for efficiency. If you have a strict CPA target, you need Bid Cap.

Lowest Cost (The Gas Pedal)

How it works: TikTok gets you the most conversions possible for your budget, regardless of cost. Use Case:

1. New Account: You need data fast.
2. Viral Creative: You have a video with high CTR and want to max it out. Risk: On bad days, your CPA will skyrocket.

Bid Cap (The Brake)

How it works: You tell TikTok: "Do not pay more than $20 per conversion." Use Case:

1. Scaling: You want to spend $1,000/day but only if the CPA is profitable.
2. Stability: You want to avoid the "rollercoaster" of daily volatility. Risk: If your bid is too low (e.g., $15), you will get Zero Delivery.

The Strategy: Surf and Protect

1. Launch with Lowest Cost to test creative.
2. Once Validated, duplicate the campaign and switch to Bid Cap.
3. Set the Bid at 1.5x your Target CPA initially, then walk it down slowly.

Summary

Use Lowest Cost to find winning ads. Use Bid Cap to keep them profitable at scale. Control the machine; don't let it drive you.