This is a good question and hard to answer.
For me, I will use Social media to increase SEO visibility and making a blog for eCommerce site and posting more articles into it. This will help will organic traffic for your blog, also to your eCommerce site.
waiting for any other best ideas..
You need to promote your sites using some SEO Techniques. Placing Classified Ads and Social Media promotion like facebook, Google + would give more visits to your website. Google Ad-words is best option to get a quick start of your business. These ads will get approved and start displaying on google instantly. You can get targeted traffic more quickly and expect cash flow.
Sorry guys but Social media don't have anything with SEO its just bring traffic.
But If you need seo for Ecommerce you have to provide good description for product.
Blog / post with review of that product.
you can make video and upload on YT and include in your blog or just put link to product.
And don't use amaz.. title for your products if you sell things what is listed there.
You can write post related for that product example: "What can you do with..." " how that .. can improve your ..." and something like that.
Think what do you want to know about products and write that.
You can create group in FB to interact with your customers ask for reviews opinions.
You can write comment on related blogs, give information on related forums and that way drive traffic too.
In order to promote your website and to increase organic traffic, I would suggest you to use SEO, I think at first you need to learn from many famous and largest websites about SEO such as: Searchengineland, Searchenginewatch, Searchenginejournal, Moz,...they're all giving free basic SEO techniques that you can follow up and practice as well. After that, you should apply these techniques on your own website with your domain and hosting, try your best to practical daily as much as possible.
I believe that you can get the archive after some months you try hard.