If I submit multiple articles to the same article directory like ezine, does it help? I heard that backlinks are counted once from a respective domain, if i am submitting more than once, will it benefit me in terms of SEO?
As long as that directory does not use "nofollow" tag for backlinks, submitting more articles will help you in terms of SEO. What is counted is the number of pages that link to your page not the domains, when it comes to SEO. That means you could have 100 backlinks from a signle article directory if you submit 100 articles on there.
Of course it helps. Although you could go one step better and rewrite each article to submit to other directories.
Post unique original article in article directory really help and you can submit more than one article to the same, for your each article one backlink is counted bcz for each and every article the link is build different so it counts as different backlink.
This is of course only if you're using the articles exclusively for backlinks. If you care about the traffic-generating part of article marketing at all, then posting multiple articles on a directory becomes an absolute no-brainer.
Yes you should make sure you submit more than one article to each article submission site. Search on this forum and you will find lots of great info on article marketing.
You should always diversify by spreading your articles out amongst a few websites, submitting to just one isn't going to really 'hurt'' you but you could be missing out on readers who visit different article directories.
Why not? if search engine indexed the page, it could get you backlinks, and each article would has people to reading,and then it also could get you traffic.