That is right. If your stronghold is online promotion, then having social media accounts is best for your business. It will help you reach to your target audience easily. But if you only operate offline only, no need for social media.I think it depends on individual. I don't see it as a necessity to have social media accounts for business. But if you want to target people on social for your product promotion, then it's important that you have social media account for your business.