CainIV - 12:54 am on Mar 13, 2011 (gmt 0)
The biggest thing to remember is that actions on Google's part are not often immediate, especially in the case of off topic / irrelevant links.
However once the website hits top ten for any money terms, there are now eyeballs on the website - and backlinks - and this is where a spam report might be viewed, if initiated from a competitor.
It's much more difficult in my opinion trying to assess and learn what links demoted a website than it is to simply build a strong, quality link program from the beginning.
And if you are doing this with only high quality links, you will find you need less links than you might think to achieve favorable results.