Linktoberfest!
Content Distribution
Links from press releases, article marketing, guest blog posts, aggregated links such as RSS feeds

How to Obtain:Write unique SEO optimized content, publish, promote via social networks

Difficulty Score: 1

Quality Score: 3

Blog/Forum Comments
Links from forum signatures, posts, profiles, and blog "signing"

How to Obtain:Search relevant blogs & forum topics, register, create profiles, create anchor text signatures for forums

Difficulty Score: 1

Quality Score: 2

Purchased Links
Links obtained through direct exchange of money, includes directories

How to Obtain: Search for keywords + sponsor, advertise, sponsored by, banner ads, submit URL, add URL

Difficulty Score: 1

Quality Score: 2

Reciprocating Links
Links from partnerships, exchanges, and trades (use sparingly, stay topically relevant)

How to Obtain: Use only highest authority relevant sites to exchange with, try to do a 3 way instead of reciprocal

Difficulty Score: 2

Quality Score: 1

Social Media/Bookmarking
Links from various social media profile pages and bookmarking tools

How to Obtain: Find top bookmarking sites based on PageRank, Alexa, dofollow and submit website using good keyword anchored phrases

Difficulty Score: 3

Quality Score: 3

Embedded Content
Links via widgets, infographics, badges, and other embeddedable content

How to Obtain: Create visually appealing and useful content, promote via social networks

Difficulty Score: 3

Quality Score: 4

Link Reclamation
Links to no longer available resources to re-point at your pages

How to Obtain: Check Google Webmaster Tools for pages not found, contact websites linking to those to change link or redirect on your site

Difficulty Score: 3

Quality Score: 5

Natural Links
Links gained naturally due to link worthy (viral) content, link baiting, etc.

How to Obtain: Create good, informative content and promote through your networks

Difficulty Score: 4

Quality Score: 5

Link Requests
Links acquired through manual requests from webmasters, site owners, etc.

How to Obtain: Conduct competitive link analysis, use search operators, keyword searches, manual email requests

Difficulty Score: 5

Quality Score: 5

PR1
Equivalent To 11 Average Links
PR2
Equivalent To 58 Average Links
PR3
Equivalent To 296 Average Links
PR4
Equivalent To 1,520 Average Links
PR5
Equivalent To 7,816 Average Links
PR6
Equivalent To 40,185 Average Links
PR7
Equivalent To 206,611 Average Links
PR8
Equivalent To 1,062,280 Average Links
PR9
Equivalent To 5,461,663 Average Links
PR10
Equivalent To 28,080,881 Average Links