I have to state that it is my first post here. And I am not a native English speaker. So I'm sorry if what I say may make you confused. I will try to make my words clearly. I am here for asking help. I know there are many experts on this site. Here it is: Our website has been created for nearly 10 years. But some of the main keywords rank on the fourth page of Google. Our website is famous in our field. But many of other small websites rank better than our website. I guess our website is punished by Google. But I do not know the reason. I deleted hundreds of affiliate links in our page last week. All these websites are much like spam. But it seems the keywords rank is not improved. We've written many PRs in the last two years. Almost all of them are published on prweb. We write at least 5 PRs a month. Sometimes, even more than 15 PRs. We also used many anchor texts linking to our homepage in those PRs. All these PRs drove much traffic. But this year, all the ranks are low. We've stopped publishing PRs. At most one pr a month, not published on prweb, but some other news site. So I guess these PRs are the reason why our keywords rank low in Google. My questions is: Should I delete those PRs? Or are there any other possible reasons? Thanks for taking your precious time to read my post.