Hi there, tier 1, 2 and 3 basically is a pyramid scheme for how the links are built. For example you have tier 1 links which are very powerful, they could be web 2.0s. A web 2.0 is basically a free website, so if you go to wordpress and make a website with a .wordpress.com subdomain, that is a web 2.0. In the web 2.0 you can post an article with content and in that article add a hyper link that links back to the site that you're trying to rank. Once you have several web 2.0s that is your tier 1 links.
Tier 2 links can be contextual links. A contextual link can basically be another web 2.0, meaning it can be made on a wordpress subdomain as well. This time the content is relevant to the content in the web 2.0. Tier 3 links are massive GSA blasts, links like profile links, blog comments, basically any short links. These links can be bought in mass from various places, from here in the marketplace or at fiverr for as little as 5 dollars. The way the links are set up goes as follows: tier 3 links -> tier 2 links -> tier 1 links -> your money site or in your case your affiliate site. The links are suppose to link to each other in that order to build a pyramid scheme and pass link juice
A PBN is a private blog network. It's a network or a complied list of a bunch of high authority and powerful websites. All these websites are under the control of the PBN owner. The PBN owner can use these powerful high authority websites to post content and backlinks to them. These backlinks are obviously links to the website that he is trying to rank. In a way, a PBN is like a web 2.0, but a PBN has much more authority and power behind them, which is why they are better. Usually PBNs are made from expired domains, domains are selected based on the quality of the back link profile, domain authority, page authority, etc. All these factors are considered when picking a domain for a PBN. In general, building a PBN can be very expensive, costing several hundred dollars. This is because registering tons of expired domains costs money.
If making your own backlinks from scratch sounds overwhelming to you, you can simply buy them. In the market place there are SEO packages that'll deliver to you tier 1, tier 2, and tier 3 links. You can also buy PBN links but these are fairly pricey, about $100-$200 for small to medium packages. Do be aware that simply buying an SEO package does not mean instant ranking to page 1. You may still have to build some high authority links on your own, work on your on-page SEO, get social signals (which you can buy but it's better to seem legit), and generally it helps to be building links throughout to seem as natural as possible
