Use Google's disavow tool - detailed description here: https://support.google.com/webmasters/answer/2648487?hl=en

True, there is obviously a lot more to SEO than just filling meta-tags. My example above was just something we do for categories and obviously elements such as TITLE, H1-H3 are important.

I would look at SEO in eCommerce holistically:

• Understand your product category taxonomy and related categories. Provide a mechanism to "boilerplate" tags important for SEO. This also should include microdata such as breadcrumbs.
• Provide a "fall-back" mechanism if your content team fails - i.e. if your product team introduces new categories without SEO meta-data, craft them from the information you know about the category (i.e. category title and generic keywords)
• Don't forget about pushing Sitemap data to Google - this will push your whole taxonomy and products into the index.
• Ensure that your search indexes (many people say don't but we have not found an issue with it).
• Pay attention to canonicals for both products and categories and ensure that all links are SEO friendly
• Craft your brand verbs (buy, sell, cheap etc) in searches and categories

I think it is more important to have a high index-ratio in search than stuffing keywords which result in irrelevant search results. Over 80% of our products get indexed through Google and since we have mostly user-generated content, we ensure that the meta-data for the products is good.

If your client has a product catalogue SEO becomes a lot easier, as data should be very structured, but it will be challenging since the same content is syndicated to many other competitors.

I honestly would not stuff keywords like that. Meta tag keywords and descriptions should hint at the actual content on page.

Our site-structure for eCommerce categories consists of the following (here is an example

• Meta tags with keywords and description
• Content lead-in (text below the banner)
• Subcategory links and content
• Content lead-out (text below pagination)

Each category has the same structure and our product team manages the actual content. This works very effectively.

I would honestly exclude all your internal search pages from the Google index via robots.txt (noindex) exclusion. This will at least re-distribute crawl-time to other areas of your site.

Just having the noindex,follow in the meta-tag (without the robots.txt exclusion) will let GoogleBot crawl the page and then eventually remove it from the index.

I would also change your search-page canoncial to the search term (i.e. /search/iphone) and then have a noindex,follow on meta-tag.

I would start with a robots.txt like the one below and add in anything else you don't want to be crawled/indexed:

Sitemap: http://www.example.com/sitemap.xml

# Google Image
User-agent: Googlebot-Image
Disallow:
Allow: /*

# Google AdSense
User-agent: Mediapartners-Google*
Disallow:

# digg mirror
User-agent: duggmirror
Disallow: /

# global
User-agent: *
Disallow: /cgi-bin/
Disallow: /wp-admin/
Disallow: /wp-includes/
Disallow: /wp-content/plugins/
Disallow: /wp-content/cache/
Disallow: /wp-content/themes/
Disallow: /trackback/
Disallow: /feed/
Disallow: /comments/
Disallow: /category/*/*
Disallow: */trackback/
Disallow: */feed/
Disallow: */comments/
Disallow: /*?
Allow: /wp-content/uploads/

I suppose one easy way via robots.txt would be a NoIndex / Disallow across all content on the new site. And with this you would only measure new brand/page design.

If you are not really that interested about SERPs but the user traffic and the look and feel, why don't you try A/B testing?

I think running two different domains will not really validate much as you are not covering indexing (due to canonicals) and will probably only rank on the new domain/brand for your landing pages.

Is the intention to eventually get rid of the old domain/brand (provided that the new one is successful)?

Duplicating a domain would mean that you would pay extra for PPC (driving different brand terms) and would also mean that the reskinning would include some brand-term landing pages.

I don't think your new site will take off from an SEO perspective - especially considering that it will take about 4-8 weeks for the index to properly build out and you will only know about any duplicate content issues after it happened.

I think "trying out a new brand" is a bit dangerous, by just duplicating content on another domain and slapping a new skin on it. Unless of course the current domain does not have much SEO value with regards to branded keywords.

Depending on the number of products I think it would be better to pull up the new domain with a set of landing pages (preferably covering some of the most revenue-driving and least revenue-driving products) and a set of product pages with canonicals to the new domain and sitemap for the selected set of products and then setup PPC and funnels and do a side-by-side comparison.

If the new domain/SERPs/conversion performs better, 301 the old domain to the new one and move your products over. Anything else feels like being half-pregnant