While looking to build some quality back links it crossed my mind I should try to pinpoint what exactly makes up a good back link source. So I elaborated:

Seven Questions to ask yourself every time a new linking opportunity shows up:

1. What's their own backlink portfolio?

Well established sites appear in prominent submission directories like DMOZ and Yahoo Dir.. Their information is constantly back linked throughout the market they operate in, not to mention the buzz (followed by additional backlinks) they generate in the social environment attached to that market.

Then again, there are a bunch of webmasters that focus on getting backlinks regardless of the niche the recipient is in. Linking partnerships with these SEO novices should be excluded from the very beginning.

Good analysis for link structures are obtained fairly cheap with different SEO instruments available today.

2. Do they have comprehensive content published on their site?

Take a good look of the articles, videos, etc. published on the site and see if they correspond to your reader's needs.

If not only both of your content packages are in alignment, but there is also room for improving your current number of readers, then by all means ask for a back link and build a relationship.

Keep in mind that before optimizating for the search engines you have a content-hungry audience to satisfy.

3. What's the PageRank of your targeted webpage?

Do not just look at the PageRank assigned to the site's homepage, instead go deep and find out exactly what PR value has the webpage you intend having the link on.

This consideration applies often to blogs where posts are rapidly disappearing from the homepage along with the privileged situation of having a back link from a website with PageRank, say, of 5 (dictated by its homepage). Of course blogs are well dealt with by the search engines and this authority isn't passed and taken away so easily, but this is a general presentation to give you an idea of how PageRank flows.

The only requirement is for the overall site to be of quality and have a progressive growth. Even though the targeted page has low authority go ahead and negotiate the back link.

4. With whom do these sites entertain SEO and social relationships?

Recognized websites form and are members of vibrant online communities.

They're simultaneously referred by and referring trusted websites.. With this considerations in mind look at your possible linking site and see where do their outbound links point to.

If it doesn't link out to other themed websites, then it probably has no authority to share and it's not worth the effort of reaching out for a back link. Not to mention the increasing discontent that Google manifests towards webmasters that act greedy in preserving their PageRank by not linking out.

5. Are they organizing "link auctions"?

If this happens they probably sell links in large volumes.

You should stay away from these link farms because search engines constantly demote the link equity for these sites and when this happens your investment becomes futile.

6. Are they indexed on a regular basis and present in the search results for your niche?

In order for the link to have the barest amount of efficiency it must come from a site that ranks in the niche your in. The minimum requirement is to show up in the first four SERP pages.

Even the 3rd page isn't that good but there is room for future improvements. Tools like SEO Digger and Compete.com will help you.

7. Are they popular throughout the community?

If the answer to this one is yes, then you stand a good chance of increasing the readership you currently have. Popular websites with active audiences are the perfect source of referral traffic. Placing a link on one highly visited page can explode your website traffic overnight. Checking subscribers stats can be done with Google Reader.