Hi! In June 2015 I've started a semi-big domain consisting of around 400 product-categories with affiliate products and some content below the products for SEO-purposes. I've not built any backlinks apart from a small expired-domains-PBN of 5-7 domains and a few blog comment backlinks here and there. In January 2016(season time for the products) I had 800-1000 unique visitors daily and at off-season times around 100 visitors daily. In the midst of december 2016 an algorithmic penalty(or so I thought) hit me and I lost pretty much every top rank I previously had had. Over the course of the next 1-2 months I greatly improved all the content on the domain by a lot. Texts now have external and internal links, images and embedded videos added. My ranking situation has still not improved at all - it is rather going downhill with many ranks moving from 20-30 to 30-60. Is there any use in just deleting my domain and moving its entire content onto a newly registred url? I would then also build backlinks consistently, which I have not done on the old one. Does anyone have experience with websites not recovering from a hard hit by google and just starting the project again on a different url? Sorry for the long text. I hope there is someone out here kind enough to give me some advice.