From got I gather on this entire post, everyone could agree on the following:
- Unique Content
- Social Networking & Bookmarking
- Free Classfieds
- Articles Submissions
- Forum Signatures
- Web Directory Submissions
- Link Baiting
- Blog Comments
- Online Video
- Reciprocals
- Press Release
- Free Ebook, Newsletter, Giveaways
- Onpage Optimization (Title, Descriptions, Image Tags, SE Friendly URLs)