Social Media Management Service (Monthly Fee)?

Hi, I am looking to resell a service that will manage and advertise social media accounts on a daily (or mostly daily) basis for a monthly fee that I can resell to my clients for a slightly higher price, along with some improvements of my own.

Do any of you recommend any service like this?

EDIT: I have found a site called $99 Social. Have any of you heard of it? Any thoughts?