Have you guys actually tried ranking for high competition keywords versus low competition words? Does it just take you longer to rank for high competition or are you completely unsuccessful?
A word like "MP3" gives you 6 billion results on Google. This is not doable. A longtail phrase like "cure my snake phobia" .. gives you all of 50 thousand results, and only 61 results when put within "inverted commas" This is doable. It's fanciful to think one can get high rank with extremely competitive keywords, without a large marketing budget. At the same time, there are other factors in weighing up how competitive a keyword is, such as the PR of the top search result(s) And of course you have to factor in the value of the keyword in terms of monetization. I would rather 1,000 hits for "buy dating ebook", than 5,000 hits for "free dating ebook". Good luck.