I've been using article marketing for a while now, and it definitely does work. It's not some instant, all powerful thing though. You just have to keep chipping away at it.
There's no doubt that a lot of people think that it's highly overrated, however. One criticism of the method that I've seen repeated a few times is that soon after you submit your article to a directory it just goes to the bottom of the pile and is not seen again - or seen less and less frequently.
But I know for a fact that this is not true - at least not in quality directories like Ezine Articles. I just looked through my stats in that particular site and chose some articles I'd submitted over a year ago. It didn't matter whether they got a decent amount of traffic or almost none at all. They were still attracting pretty much the same number of views as when I first submitted them. (This is also true of my stats in Articles Base, which I checked a few days ago. This wasn't true for very topical articles, however, and for obvious reasons.)
I didn't look at all my articles, so my conclusions may not be completely accurate. But it does seem that articles just keep on keeping on pretty consistently once you've submitted them.
This may be different for other, smaller article directories but I can't see why that would be. As long as the directory is reasonably well run, it will keep amassing more content and gain more credibility in search engines. Also, if you look at the top articles listed on some of the smaller directories you'll see that some have amassed very high numbers of views over the years.
So, even if you're submitting articles mainly for the clicks to your site rather than for the SEO benefit this is good news. Each article is like a little gift that just keeps on giving. The whole effect is cumulative.
Say you submit 25 articles that each attract an average of 10 views a week. That's 1000 views a month. Now if you have a click through rate to the site listed in your author bio-box of about 2 percent, which isn't hard to achieve, you've got 20 hits a month from that batch of articles alone for as long as the directories exist.
Okay, that doesn't sound like much. But remember that just keeps on going no matter what. It might wane over a long time, but this would be a very slow process.
And if, in a year, you end up with 100 articles out there getting seen at that same rate (that's an average of 2 articles submitted each week - again pretty easy to achieve) then you'll have 80 hits a month, or close to 1000 hits a year. And that's just from clicks.
Then there's the search engine benefit. Particularly if you're submitting to lots of different directories, those 100 articles will help you a great deal. I'd say that even if you don't do much keyword research your site is sure to hit the first page of some good long tail searches, which will also bring you some solid, targeted long term traffic.
For these reasons I believe that article marketing is still very much worth it - particularly as a long term strategy.