Big waste of time. You see, I have a website at Free Piano Sheet Music in the New Age Style that was hovering in the top 20 (usually at the bottom) for the search term 'free piano sheet music.'
I hadn't updated the site in a long time and thought ... why not just add some new posts to this Blogger blog. I did and within 48 hours I was #1 for the same search term. BTW, 'free piano sheet music' is a very competitive search phrase.
How many backlinks do I have for this site? A huge number ... 4.
So, what did I learn? Google wants FRESH CONTENT! That's pretty much it and the sites that provide it will be rewarded with high ranking in the serps.