Using social media is only as important as you want to make it! So setting your initial goals is good. Do you want new clients? Do you want to make sales? Or is your goal to grow a following you can then leverage for ad sales? Depending on that you can then take into consideration how you work with your social media sites.
It is important to post consistently regardless your goal – but depending on your goals will change how you market. EX: If your goal is to make sales you need to focus on finding what type of post and scripting draws new sales in. You only need one buyer to make a sale (number of likes might feel important but at the end of the day that doesn’t always convert to a sale).
So first define your goals and then you can define how important social media marketing is to you!