A little confusion about article marketing

I have been regular on this forum from the past 2-3 weeks and I've also come across some amazing success stories here. And also methods which can generate an income in a week. All these methods have one thing in common and that is article submission. Everybody says find keywords, make SEO articles on them and submit them to article directories especially ezines. My doubt is how does it bring the traffic and how does it help the rankings?

Suppose, I nail down 100 keywords related to my niche and I write an article on each of them and submit them to article directories with my link at the bottom. Ultimately I'll need people to read my article to get visitors to my site. Now here's the question, how do I get visitors to my article in the first place? Is it just the people who use the "search" function on article directories that land up on my website?

Also, as I write 100 different articles for 100 different keywords then it is also possible that the anchor text may vary for each article with respect to the keyword. How does that help the SERPs? And even if it does then its like just one backlink for each keyword!!!

I hope you guys are understanding my logic here and can kindly explain the meaning of article submissions to me. I know about the algorithm change that took place on Thursday but I've heard people say that article submissions still help.