There is no doubt that links from other websites to your website is vital for an ecommerce business. It all filters down to the Google Page Rank. This is the Google tool that is used to determine how important a website is to people surfing the net.
Google will balance the number of links, the PR of the pages exchanging the links, the keyword similarities on the linked pages, how often the site is updated, and the number of hits a site receives. Two PR 4 sites sharing links between pages with small business as the main keyword, will benefit more from a small business website with a PR4 and a private blog that discusses wealth building.
Also, 100 links between a PR6 site and a PR4 site will increase the ranking of the second site faster than 100 000 links from a PR2 site and the same PR4 site.
This can all be a little confusing. Googles PR algorithm controls everything. The confusion comes from the fact that search engines cannot think. Both the PR4 small business site and the PR2 wealth building site can be helping small business owners improve their page promotion. However, search engines cannot read. If they dont see similar keywords, then they do not...