It's true. Rewards close after 7 days. Here is a tip. If your content is current and valuable to new users (your followers increase with time and so do Steemit users), you can refresh that content, improve it and post again to earn from well performing content. It will add value to Steemit and benefit you as well. It's your own content and not present anywhere else on the internet (except your own Steemit blog) so it's not unethical. I say that on authority of some senior members who have considered it an acceptable practice. Please upvote this comment to make it visible to all. Thank you and thank me later.