Search Engine Optimization is a topic with many unknown variables. Google doesn’t divulge how their search engine works and many try and break the code. Because of that alone there are plenty of ideas that are usually unproved. The way to test those ideas is to perform a series of experiments like Commission Blueprint did with their PR to content link experiment. They have tested 100s of sites over a period of a year. This sort of test is statistically significant and proves the theory. In this situation, incidentally, the link of PR and content was proven to be non-existent.

Keyword research is crucial for most of the internet business. So it’s important to do it correctly. And to do that you have to understand the most significant information of a keyword. They’re as follows. Firstly, the visits that a keyword gets is critical - you want to get visitors after all. Next it’s the competition - the less the better. Competing for big keywords takes lost of time, so you could be better off with easy keywords first. Use keyword tools to make the keyword research more efficient, I like to recommend Keyword Elite. There are way more variables, but those are the most vital.