I have never seen a strategy work so well than this one alone. It is a bit difficult and requires consistency as well as a bit of money. Make sure you have your on-page optimization correct when using this method. It will make your life much easier implementing these off-page link building strategies.
I personally was able to take several sites with very challenging keywords from the bottom of page 2 to the top of page one in the serps with this method in 2 weeks.
What do you guys think about this? Is it blackhat, whitehat, or grayhat?