The Boost button on Instagram and Facebook is the quickest way to put money behind a post. For many local businesses it's the only kind of ad they have ever run. It works, but it hides most of the controls that decide whether an ad brings customers or just views.
What Boost does
Boost takes a post you have already published and shows it to more people. You choose a goal, a rough audience, a budget and a duration. That's all.
Because the choices are limited, Boost is good for one job: getting more eyes on a post quickly.
What you give up
You can't test several versions of an ad against each other, so you never find out which image, video or headline works best.
Targeting and placement options are narrower, so budget is often spent on people who were never likely to buy.
Results are harder to connect to enquiries and sales, especially without the Meta Pixel set up on your website.
When Ads Manager is worth it
If you want leads, WhatsApp chats or sales rather than likes, Ads Manager gives you the objective, the testing and the tracking to get there. It takes longer to set up, and it rewards that effort with clearer numbers.
A sensible approach for most local businesses is to keep Boost for occasional announcements and run lead and sales campaigns from Ads Manager.