Social media and building your brand is all about attention. You simply cannot get the attention you need by posting once a day or less.
90 posts gives you the opportunity to control what you post and still be posting more than your competitors.
No, you can't. Anyone who tells you something like that is lying to you.
The formula for Social Media success is this
1. Post more often.
2. Post better content.
3. Communicate like Crazy.
Our posts are just a start. If you don't add in great content of your own and communicate with your followers - you are wasting your time.
You can use as many as you'd like. We recommend at least 2 every day and we find that best practices dictate that you spread them out.
Each platform has statistical information available and you should take advantage of it to learn the optimal times to post.