Link building is something very important to all bloggers and webmasters. It can be black-hat or white-hat whatever. But recently a lot of blogs has been affected by Google's algorithmic change- the main reason is- a lot of spam links and unnatural link building. Though I didn't get any mention on Search Engine Land or MOZ, still here is a link for you for better understanding about some top google's algorithmic changes for providing the better search result to visitors- https://searchengineland.com/library/google/google-algorithm-updates. Even one of my sites has been affected for that, and in that case, recovery is really tough and time-consuming definitely. I built too much spammy comment backlinks for that site to rank well on SERP. At that moment I ranked on the top too, but right now, according to the latest algorithm, it's a wrong practice that I have done. So I have to be careful and not to create spammy backlinks anymore. Backlinks are very important to increase domain authority, but spammy backlinks can lead your website from page one to page 20. Even 5-6 years ago, event blogs created too much spammy link for ranking on page one. But nowadays, you can't totally depend on comment backlinks. Like there is a draft saved on your doc/docx file, and you are doing copy-paste continuously on different sites. A comment should be written in a very natural way, topic-oriented, that adds value to the topic as well as article. There are few options while writing a comment- name, email, website, comment. You can write a comment that really oriented to the post topic and mention your site there. But nowadays I have seen several WordPress blogs, they have removed the option to put your website URL in the comment section. I was looking for some gigs related to link foundation and 3 tier link building. But what I have found- there are a lot of gigs. Basically, they claim to provide you with all hand made white-hat links. But I have high doubt on this issue. Will they create 2000-3000 comment backlinks on tier 3? Most probably no. Here are few gigs with screenshots. One is from Fiverr, and another is from Seoclerk.  
backlinks package 1

backlinks package 2
To play the safe game in this SEO field, it's better to stay away from all these link building gigs and focus on your content. Quality content can bring a lot of backlinks and visitors as well. For example, if you search for "Google ranking factors", is the first site, that will appear on the Google search result. The article was written probably 3-4 years ago. And still, it is the top site for that keyword. And it has a lot of backlinks, from renowned blogs like SearchEngineLand, neilpatel.com and many more due to its quality and presentation. No more now. If you have any question or query related to this article, feel free to ask me here. Just do drop a comment below the box. And if you find this article share-worthy, then please share it with your friends via Facebook, Messenger, Google Plus, Twitter, Pinterest, WhatsApp etc. Take care.