Thank you for your excellent response, Alan.

Reviewing my post, I did not explain the situation 100% accurately.

Rather than integrating all our shops, in fact we would just be taking one of the shops we run, our main site, and wondering whether to consolidate with two new shops running on two new domains (these domains being excellent keywords).

An important point is that we changed the name of the site and domain name mid-2011, to a more international name. At first this clearly had an effect on our Google ranking, although having just had the best Christmas sales ever, we feel this has succeeded. (301 redirects were set up)

It would appear that the decision whether or not to integrate now to a unified domain would be affected by this fact. The name of our current main site would not be suitable as an umbrella term for all.

Thanks for your suggestion, Shane, this is certainly what we can see as a potential advantage, for that way of going.

Our company runs a number of individual online shops, specialised in particular products but all in the same genre of goods overall, with a specific and relevant domain name for each shop. At the moment the sites are separate, and not interlinked, i.e. Completely separate brands.

An analogy could be something like clothing accessories (we are not in the clothing business): scarves.com, and silkties.com (our field is more niche than this)

We are about to launch a related site, (e.g. handbags.com), in the same field again but without precisely overlapping products. We will produce this site on a newer, more flexible e-commerce platform, so now is a good time to consider whether we want to place all our sites together with one e-commerce system on the backend.

Essentially, we need to know what the pros and cons would be of the various options facing us and how the SEO ranking is affected by the three possibilities.

Option 1: continue with separate sites each with its own domains.

Option 2: have multiple sites, each on their own domain, but on the same ecommerce system and visible linked together for the customer (with unified checkout) – on the top of each site could be a menu bar linking to each site:

[Scarves.com] – [SilkTies.com] – [Handbags.com]

The main question here is whether the multiple domains are mutually beneficial, particularly considerding how close to target keywords the individual domains are. If mutually benefitial, how does it compare to option 3:

Option 3: Having recently acquired a domain name (e.g. accessories.com) which would cover the whole category together, we are presented with a third option: making one site selling all of these products in different categories. Our main concern here would be losing the ability to specifically target marketing, and losing the benefit of the domains with the key words in for what people are more likely to be searching for (e.g. 'silk tie') rather than 'accessories.'

Is it worth taking the hit on losing these specific targeted domain names for the advantage of increased combined inbound links?

Thank you for your excellent response, Alan.

Reviewing my post, I did not explain the situation 100% accurately.

Rather than integrating all our shops, in fact we would just be taking one of the shops we run, our main site, and wondering whether to consolidate with two new shops running on two new domains (these domains being excellent keywords).

An important point is that we changed the name of the site and domain name mid-2011, to a more international name. At first this clearly had an effect on our Google ranking, although having just had the best Christmas sales ever, we feel this has succeeded. (301 redirects were set up)

It would appear that the decision whether or not to integrate now to a unified domain would be affected by this fact. The name of our current main site would not be suitable as an umbrella term for all.