Participation on forums as a method of direct customer acquisition doesn't scale. This isn't to say that it is valueless, but if you're recruiting your new trial users by individual persuasion you had darn well better me selling at Big Freaking Enterprise price points. Otherwise you are spending a huge amount of effort buying yourself a below minimum-wage job. Unless something has changed drastically in American college students in the last five years, you are probably not selling them enterprise software.

Ditto Q/A websites. By the way, you know they're essentially just massive funnels for low quality UGC to choke search engines with, right? (I will give an honorable exception to StackOverflow because some of their answers actually contain useful information that could not be gleaned from a Google search, and the embedded MMORPG is kind of fun.)

Put the content on your own darn page and disintermediate the middle man. (SEO is free (well, freeish) and effective, although it is neither quick nor particularly easy.)

There is a tradeoff between quick, free, easy and effective. Its impossible to learn such techniques on a blog, because any quick, free & easy method would draw the crowds, rendering it ineffective.

Besides, the author's suggestions involve spending time answering and searching forums. Not my definition of "quick".