to be honest Ezines are going to yield smaller results, you really only want to target the big ezine websites which are high quality and indexed by Google news.
In regards to what other strategies you should use to build backlinks for your ecommerce site some good posts can be found here:
http://www.seomoz.org/blog/creative-link-building-for-ecommerce-sites
http://backlinks.com.au/15-ways-to-build-backlinks-post-google-penguin-update/
I would look at using more of the above methods over lower quality article submissions