Link Building strategies 

Link building is the practice of getting other sites to link back to your website. This can often be done using a wide variety of strategies, such as:

Asking for a link
Giving away content or tools
Widget development
Social media campaigns
Purchasing links and more….
But first, let’s start with the basic theories…

* Why Link Building Matters

Whenever any user enters a query into a search engine, the search engine needs to determine how to return the best results. How? There are two key steps:
Figure out which pages on the web are related in any way to the query
Evaluate which of the pages that relate to the query are the most important
Each link to a web page is seen as a vote for that web page.
In simple terms, if there are two pages that are equally relevant to a given search query, the page with the better inbound link profile will rank higher than the other page (being all other factors equal).
Hence, the need of Link Building!

*How Search Engines Evaluate Links

Each link to a web page is a vote for that web page.
That implies the higher the PR, the more the value of that vote. This is partially true. But, two votes may not have equal weight even if they are from same PR page.
Value of vote depends on – Relevance and Authority
Now let’s take a deeper look at these factors…

* Relevance Factor

Theme of the linking website
Purpose of the linking website
Topic of the linking page