Hi,
Consolidating sites for manageability and traffic is often a good decision, we did it with some of our smaller sites and saw some good successes with it.
The pros are, as i see it;
- Easy to manage the sites content (if you have an easy to use cm system on the main site)
- Generating unique content for 1 site is easy than generating content for several site and will hopefully lead to a situation where the main site is seen as an authority.
- Consolidation of your traffic should make it easier to target the keywords you know are performing well for you as opposed to having to pull from several different analytics sources
- With your site being transactional it might be easier for you to manage orders on one site than on several depending on how your back end system works?
Cons would be largely around the potential loss of traffic, having gone through a similar consolidation process I think it is best to assume you will save around 85% of your search results, although reports differ on this one. Once you make the switch, you will see an initial drop in traffic but should recover if done correctly.
There are a number of steps involved in doing this effectively:
- Ascertain which of your keywords, and consequently pages, are vital for you to keep. You can do this easily with the keyword/content reports in google analytics.
- I would put in place individual 301s on these pages pointing to most relevant pages on your main site. From experience I would suggest leaving these 301s in place until you start seeing the positions in the SERPs change over to your new results.
- It's probably worth running an OSE report and double checking of any of the external links you have to your smaller sites can be altered to point at the new one - this will probably be more efficient than the 301s.
- Having protected the main pages start focusing on the rest of the pages on your sites. Don't do a blanket 301 as you'll end up with a bunch of 404s from the pages you miss. It'll take much longer to do this page by page but it'll be worth it in the end.
- Finally, in the webmaster accounts of each of your sites there is the option to inform google that your site has moved. Once you're happy with the 301s for each of the smaller sites.
Just a few tips here, more focused on moving one site over to a new domain, but should definitely be considered for a site consolidation too. The google article on moving domains will also be helpful as well:
https://support.google.com/webmasters/bin/answer.py?hl=en&answer=83105
Nice little Moz bit on redirections here too if you're not so comfortable with them: http://www.seomoz.org/learn-seo/redirection
Thanks,
Nigel