Although there is no scientific answer to this great question, there are guidelines that can help you answer it for your company.
First, consider the frequency of your other major content marketing tools such as your eNewsletter. Since these foundational tools help seed the content for your social media posts, their frequency will determine how much content you have readily available to spread out over a social media posting schedule.
Consistency is critical to successfully managing your social media efforts, but you need to test the tolerance of your followers. Remember that the whole point of launching a social media campaign is to keep your brand top-of-mind among customers and prospects, particularly those who follow you on social media. Too few posts may cause followers to forget about you. Too many posts may cause people to hide your posts or unfollow you. Ideally, two to three posts per week should provide a healthy balance between absence and annoyance.
Other factors to consider — and to test in the early phases — are the days of week and times of day that generate the greatest response from your social media posts.
Finally, and perhaps most importantly, be sure that whatever schedule you establish as “right” for your company is also sustainable over the long term. Social media management is a marathon, not a sprint; pace yourself so you don’t run out of steam.