• Using slang and jargon - Choose a communications style that makes sense for both your brand and your audience.
• Not having any personality on their accounts – When all you do is re-tweets or post auto-generated messages or inspirational quotes with no context, people get frustrated and leave. They want to engage or they don't want you around.  Define your brand mission and purpose before building your social media and content strategy.
• Trying to be funny – Some people are very worried about their health. When you try to inject humor and they aren't into it, you'll lose them.
• Not replying to messages – People tend to follow brands and pages from people they want to see content from, not necessarily those they want to send messages to. But the fact that this is important to 25% of consumers is significant, and likely to increase as reliance on social platforms evolves.

• Too many promotional messages
• Irrelevant information
• Tweeting too often on stuff they don't care about
• Use of slang and medical jargon
• You're too quite and don't post often enough
• You don't reply to their posts

Source: sproutsocial  Q2-2016