If you don’t want to rebuild an expired domain, just take its backlinks and allow the linkers to be aware of the “to-dead-resource” linking. You can ask a link-builder to replace non-working links with your website’s one. If the content is relevant, you can try to restore it. Be sure that you can make it better than it was before. Reach out and inform the link-builder about the renewed content.
There are several factors that determine the value of a backlink. Backlinks from authoritative sites on a given topic are highly valuable. If both sites and pages have content geared toward the topic, the backlink is considered relevant and believed to have strong influence on the search engine rankings of the web page granted the backlink. A backlink represents a favorable 'editorial vote' for the receiving webpage from another granting webpage. Another important factor is the anchor text of the backlink. Anchor text is the descriptive labeling of the hyperlink as it appears on a web page. Search engine bots (i.e., spiders, crawlers, etc.) examine the anchor text to evaluate how relevant it is to the content on a webpage. Anchor text and webpage content congruency are highly weighted in search engine results page (SERP) rankings of a webpage with respect to any given keyword query by a search engine user.
So, when you find a relevant forum, be sure that you have written an authorized profile description and toss in your main concept or word of great significance. Then study the forum, its rules, and the way it operates. Examine the forum to know whether its members share links in threads. Become a reliable person making more and more friends and placing posts interesting for the forum participants. Thanks to that you may get more internal linkage to your profile and gain authority. And, of course, threads will build your credibility.Why do you need all that?
However, if you're going to understand online marketing, you have to understand the importance of building Google's trust. There are three core components involved here. These three core components are like the pillars of trust that comprise all of Google's 200+ ranking factor rules. Each of those rules can be categorized and cataloged into one of these three pillars of trust. If you want to rank on the first page or in the first spot, you need to focus on all three, and not just one or two out of three.
3. General on-site optimization. On-site optimization is a collection of tactics, most of which are simple to implement, geared toward making your website more visible and indexable to search engines. These tactics include things like optimizing your titles and meta descriptions to include some of your target keywords, ensuring your site’s code is clean and minimal, and providing ample, relevant content on every page. I’ve got a huge list of on-site SEO tactics you can check out here.
Links - Links from other websites play a key role in determining the ranking of a site in Google and other search engines. The reason being, a link can be seen as a vote of quality from other websites, since website owners are unlikely to link to other sites which are of poor quality. Sites that acquire links from many other sites gain authority in the eyes of search engines, especially if the sites that are linking to them are themselves authoritative.
SEO experts have a really bad habit: They like to throw around strange words and industry jargon when they talk to customers without checking to make sure that their clients understand the topic at hand. Some do this intentionally to paper over the fact that they use black hat techniques that will ultimately hurt their customers. But for most, it’s simply a matter of failing to recognize that part of their job is to educate their clients. 

Search engines use complex mathematical algorithms to interpret which websites a user seeks. In this diagram, if each bubble represents a website, programs sometimes called spiders examine which sites link to which other sites, with arrows representing these links. Websites getting more inbound links, or stronger links, are presumed to be more important and what the user is searching for. In this example, since website B is the recipient of numerous inbound links, it ranks more highly in a web search. And the links "carry through", such that website C, even though it only has one inbound link, has an inbound link from a highly popular site (B) while site E does not. Note: Percentages are rounded.

Getting unique and authoritative links is crucial for higher ranking in the SERPs and improving your SEO. Google's algorithm on evaluation of links evolved in recent years creating a more challenging process now to get high quality backlinks. External links still matter and aren’t obsolete, so start working on strategies to get valuable backlinks to improve your search visibility.

Search Engine Optimization