# Glossary

> Every metric, setting and piece of jargon a performance marketer meets, with the formula and one worked example each.

- **URL**: https://marxx.ai/glossary

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- [What is CAC (customer acquisition cost)?](/glossary/cac): CAC is the full cost of winning one new customer, across ads, tools and team. Learn the formula, see a worked example and compare it with CPA.
- [What is the CAC payback period?](/glossary/cac-payback-period): CAC payback period is how many months it takes a new customer to earn back what you paid to win them. Formula and a worked example in rupees.
- [What is CPA (cost per acquisition)?](/glossary/cpa): CPA is what you pay in ads for one customer action, such as a purchase or a sign-up. Formula, a worked example and how to set a target CPA.
- [What is the LTV:CAC ratio?](/glossary/ltv-to-cac-ratio): The LTV to CAC ratio compares what a customer is worth with what it cost to win them. Formula, a worked example and why 3 to 1 is the common target.
- [What is CPM (cost per 1,000 impressions)?](/glossary/cpm): CPM is what you pay for 1,000 ad impressions. Learn the formula, see a worked example in rupees and find out what pushes CPM up or down.
- [What is a creative strategist?](/glossary/creative-strategist): A creative strategist decides what ads to make next, based on data and research, and writes the briefs. What the role does, the skills and how it differs.
- [What is CTR (click-through rate)?](/glossary/ctr): CTR is the share of people who click your ad after seeing it. Here is the formula, a worked example, the Meta CTR types and how to raise it.
- [What is hold rate in video ads?](/glossary/hold-rate): Hold rate shows how many people keep watching your video ad after the hook. Formula, a worked example and fixes for a video that loses viewers.
- [What is the learning phase on Meta ads?](/glossary/learning-phase): The learning phase is the time Meta needs to learn who responds to a new or edited ad set. What triggers it, how long it lasts and how to exit it.
- [What are Advantage+ sales campaigns?](/glossary/advantage-plus-shopping-campaigns): Advantage+ sales campaigns, once called Advantage+ shopping, let Meta automate audience, placement and budget for sales. How they work and when to use them.
- [What is break-even ROAS?](/glossary/break-even-roas): Break-even ROAS is the ROAS where your ads pay for themselves and no more. Work it out from your gross margin in one line, with a worked example.
- [What is broad targeting?](/glossary/broad-targeting): Broad targeting means giving Meta only basic limits like country, age and gender, and letting it find buyers. When it works and how to set it up.
- [What is the Conversions API (CAPI)?](/glossary/conversions-api): Meta's Conversions API sends purchase and lead events from your server to Meta, so fewer sales go missing. What it is, why it matters and how to set it up.
- [What is MER (marketing efficiency ratio)?](/glossary/mer): MER is your total revenue divided by your total ad spend. It is harder to fool than ROAS. Here is the formula, an example and when to use it.
- [What is ROAS (return on ad spend)?](/glossary/roas): ROAS is the revenue your ads bring in for every rupee or dollar you spend on them. Here is the formula, a worked example and what a good ROAS is.
- [What is an ad angle?](/glossary/ad-angle): An ad angle is the reason you give someone to care about your product. Learn how angles differ from hooks, with examples across one product.
- [What is ad fatigue (creative fatigue)?](/glossary/ad-fatigue): Ad fatigue is when people have seen your ad so often that it stops working. Learn the signs, see a worked example and fix it before costs climb.
- [What is a hook in an ad?](/glossary/ad-hook): An ad hook is the first line or first seconds that make someone stop and pay attention. What makes a strong hook, with examples you can adapt today.
- [What is creative diversity?](/glossary/creative-diversity): Creative diversity means running ads that are truly different in angle, hook, person and format, not small edits. Why Meta rewards it and how to plan it.
- [What is ad frequency?](/glossary/frequency): Ad frequency is how many times, on average, each person saw your ad. Learn the formula, see an example and know when frequency means ad fatigue.
- [What is hook rate?](/glossary/hook-rate): Hook rate is the share of people who watch the first three seconds of your video ad. Formula, a worked example and five ways to raise it.
- [What is Meta Andromeda?](/glossary/meta-andromeda): Andromeda is the system Meta uses to pick which ads could be shown to each person, before ranking. What it does and why it rewards creative variety.
- [What is thumbstop ratio?](/glossary/thumbstop-ratio): Thumbstop ratio measures how often your video ad stops people scrolling. Formula, a worked example and how it relates to hook rate.