I agree about the company pages.
I do have a lot of unique original content, though I don't feel branded companies can connect as much as personal accounts.
Instagram is as you say a visual platform and I think its a lean towards lifestyle perceptive.
Twitter is another social platform I'm terrible at and I've never been able to go beyond that 300-500 follower count.
I found Twitter pretty pointless when I first signed up for it. I guess I just didn't really get it initially. It was only once I started discovering interesting developers to follow on it I found a use for it - mainly as a consumer. Now I use it solely for that. It helped bring order to what otherwise just seemed like chaos in the form of up to 280 characters. Personally the most interesting things I find on it are developers sharing random projects or code snippets they've worked on.
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.