Short answer
Use Boost when you already have a post that is doing well and you simply want more local people to see it. Use Ads Manager when you want something specific, such as messages, bookings or sales, because it lets you choose the goal, define the audience, test several adverts against each other and see what each result cost. Most disappointing boosts were aimed at likes when the owner wanted customers.
What each one does
| Boost button | Ads Manager | |
|---|---|---|
| Time to set up | Two minutes | Longer, the first time |
| Goal | A short list. Often defaults to engagement | Full choice: messages, traffic, leads, sales, reach |
| Audience | Basic: place, age, a few interests | Detailed, and can be saved and reused |
| Testing | One post at a time | Several adverts side by side |
| Where it shows | Chosen for you | You can choose placements |
| Reporting | Reach, reactions, a summary | Cost per result, by advert and audience |
When a boost is fine
- A post is already getting attention without help, and you want more of the same people to see it.
- You set the goal to messages or visits yourself, instead of accepting the default.
- The audience is set to your own area.
- The post has an offer and one instruction.
When to use Ads Manager
- You need enquiries, bookings or sales, and want to know what each one costs.
- You want to test two or three adverts and keep the best.
- You are spending every month.
- You want to show adverts again to people who responded before.
If you boost, check these four things
- Goal. Change it from engagement to what you actually want.
- Audience. Your town and nearby, the ages that buy from you.
- Duration and amount. A shorter run at a higher daily amount is easier to read than a long thin one.
- The post. An offer, a price or starting price, one instruction.
Why the first days look worse
Meta calls the start of any advert the learning phase. The system is still finding out who responds, and results are less stable. Meta's guidance is that an advert set needs about 50 results in a week to leave that phase. A tiny budget spread over many days may never get there, which is one reason small boosts disappoint.