image by @remygbernhardt
Boosted Posts:
+ increases the 'reach' of your post to a wider audience
+ pushes your message outside of your following
+ the simplest way to advertise on Facebook
+ lives on your pages timeline (wall or newsfeed)
+ allows your to either select an automated audience (selected by the instagram algorithm) or to an audience of your choosing
Facebook Ads
+ created through ads manager and offer more advanced customised options and solutions
+ instantly places the post/ ad on instagram and facebook (should you choose for it to go to both platforms)
+ gives you also more control of your target audience e.g. more specific targeting of your audience demographics, interests
+ allows for specialise targeting e.g. retargeting website visitors or lookalike audiences
+ allows your to choose a specific objective e.g. conversions or traffic
+ gives you more metrics to gauge success
+ over 10 CTA's (call-to-action) to choose from
In summary
A Boosted post is better for likes, reactions, comments and overall engagement. Whereas a Facebook Ad is better for strategic conversions, for example bookings, website traffic and page likes.