no one has unlocked social media in a way that demonstrates return on marketing objectives, such as reasonable expected range of outcome at for set amount of resource allocation
I think social media should be a core component of your marketing mix
What is more common is allocating far less budget to social media and looking at it more like buying a lottery ticket
There is no such thing as “free media,” free media is just media you achieve by spending your time and money on developing assets that reduce the amount of money you had to spend to “buy media.”
Achieving success in social media requires commitments longer than many campaigns are scheduled to run.
So don’t spread your social media budget over some artificial timeline created by your media plan, but regard it as an “always on” component.