Went to their site and was quite impressed with the whole proposition.
Here is some of my own experience about article marketing:
I have written some 50 articles over the last 2 years and posted them on ezinearticles.com, probably the most prominent article marketing site.
Overall articles have been viewed some 50 k times and been published by other people around 1 k times. So yes, it will generate a lot of back links.
However, many publishers will simply grab your content and publish it on some of the most gruesome websites around (not sure if that enhances reputation...) and leave out the due back links. I have seen some people running my articles through an automatic translator into German and Spanish, which produced nothing but waffle.
PR of the sites I promoted did not go up but down, probably due to the poor quality of the sites publishing your content.
I have always been fascinated with the idea of article marketing and will continue to publish, even though it has not borne the fruits I had hoped for so far.
I will try articlemarketer.com one of these days myself, but equally would be very curious about any feedback on this service.
Thanks.