Digital marketing is largely divided across 2 groups, viz., Search engines and Social Media.
For serious businesses, usually, the search engine route works well. Example, if you are marketing a real estate project, Google is the place you have to look at.
When someone wants to buy a property, he is searching in Google for the type of property he is looking at along with the geographical area. Example “Apartments in Bangalore”
So the chances of you getting inquiries are higher.
If you are trying to sell cloths or shoes or promote a movie, the social media in general and Facebook, in particular, is very effective as you can show ads, take your post viral to the correct target audience.