Why Negative SEO?:
It is a kind of fight happens between the competitor's. In simple if Someone did not like you or your business, They just start doing some unnecessary things to spam/hate your website/business in various ways.
Ways of Negative SEO:
1. Over optimization - Building tons of Spam back-links
2. Targeting adult keywords - Anchoring the website using adult key terms
3. Content SPAM - Posting your website content to 10000's of article directories.
4. Building negative reviews
5. Website hack
6. Negative social impacts - Reducing your quality of service in the social media sites.
7. WOT trust value - Building back-links to the domain - that downloads a virus or malicious code and many other ways.
Note: Please do not use the above words to SPAM a business - If someone used - I will sure start spamming them by tons of ways.
Thanks Kevin. That is a big problem. Just imagine you spend time and money on SEO and wonder why it doesn't work but it could be just because someone is doing this stuff #@$%!!!.
You're right @hellboy buddy, This is world and most interesting thing is we're humans! So it happens always., Cool and enjoy the stuff! It is also a part of SEO
It's like a an evil SEO twin I believe this only affects new website has have low PR and are still evolving. Already well established high page-rank ones are not affected. YES it sucks I know.