70 Domain Names Point to 70 Nearly Identical Inner Webpages

[netsites]

I have a new SEO client; his website has never been optimized. There are 70 domain names involved with this one website. Each domain name points to an exact replica of the main page, other than the fact that a small content box has different info in it, and sometimes the header graphic is different. So, 70 webpages that are 5% different from each other and 5% different from the main page.

How badly is this issue affecting this website's ability to rank well, and what is the best way to solve this?

[SEO5Team]

This issue that you're facing is quite common with franchise related websites as they follow one master template and just some localized content changes on each of the franchisee sites.

Each of the individual franchisee sites should invest in original content that separates it from the corporate site. Just having a 5% difference in content will not suffice and will do harm sooner or later.

A really good discussion on this topic in this Link