bucket
Yep. It's so simple. Through backlinks, testimonials can bring you continuous traffic.
You must create something of the same value to attract links. It's not necessary to duplicate the work of others, nor should you try to do it in a completely new way. You can certainly do something similar to this, but make it yours. If you want to create a widget, it can be a handy widget. If it's an odd list, make a weird list. It doesn't matter what your target market is looking for, the content you create should be useful and informative.
They were also happy to include my link because they saw that I added value twice, once by alerting them about an outdated link and then again by showing them my valuable resource.
I was also thinking of writing an ultimate guide on SEO. There are already thousands of guides on this topic.