The danger of SEO shortcuts

Traffic went from 100,000 all the way to nothing. The 2 websites that I created there, so portal2walkthrough.net and howtogeridofimples.net. At the time I was broke. I went to this website where I bought articles that were $25 or $50 and I'd buy a handful of those and then I'd buy a lot of spammy links from these websites. All of a sudden I started noticing that, wow, I was getting like 20,000, 30,000 visitors per day. It went up to 100,000 visitors per day, which is a lot. All of a sudden, maybe in 3 days or so, that traffic went from 100,000 all the way to nothing. I dropped my traffic all the way to nothing. Google's algorithm quickly picked up that I was running a lot of shortcuts and lesson learned.