If you are doing SEO of your site then you need to understand competition first, if you don't understand the competition then you may not perform well, this is the main thing, I would say.

Hello..
Competitor analysis has become one major factor.Woorank can help you to find out your competitors analyze your competitor after that you can start link building where your competitors are doing this will help you....

Yes, your pretty right knowing about competition is one of the main factor of SEO.

Then have a 100% chance of seo campaign failure so it is important to analyze of competition of keywords.

competitor analysis is most important factor in on page seo.so if we do compitator analysis we can get to know what we have to do exactly to increase our seo weightage either we should build more backlinks or we need to do meta tag optimization,content optimization and we can get know why our competitor website came in first position and what they are done to get more traffic or to increase keyword ranking.so we can start to optimize our website according them.