But the truth is that you can still build a good following on social media simply by sharing content written by other people that's of a good quality. So you hardly have to write anything yourself. You just have to be an effective guide. And you can do this quite quickly and easily.
That said, it's obviously a good idea to include your observations and advice in the form of tweets and status updates, as well as links to your own blog posts and articles if you can. Doing so will add greatly to your credibility, of course. But it's not absolutely vital.
In the same way that a critic isn't creative himself, but guides people to the best creations by others and thereby commands respect for his opinion and knowledge, you can gain credibility on social media by consistently pointing people towards quality content.
If you do this it will take a bit of work, of course. You do have to find that good stuff, and consistently. But it's not nearly as time consuming as producing it all yourself. And it's amazing how much quality content you can find online in a short space of time. As well as Googling, there's social media itself. If I find a really good article on Google Plus, for example, then I'll share it on Facebook and Twitter.
Doing this consistently keeps you in the minds of your followers and fans. Before long you'll have a reputation as someone who has a great deal of knowledge about his niche, which is obviously a great thing for anyone in business.