Since starting our business back in 2006 we've gone through alot of branding, and as a result URL and architectual migrations. This has always something that has been driven by usability, brand awareness and technical efficiency reasons, while knowing that there would be SEO hits to take from it....but ultimately hoping to have a much stronger foundation from an SEO perspective in the long run.
Having just gone through our most recent (and hopefully final) migration, we are now about 15% down on traffic (although more like 35% - 40% in real terms when seasonality is stripped out). Below is a timeline to our structural history:
2007 - 2009 = We operated as a network of inidividual websites which started as 1, www.marbellainfo.com, but grew to 40, with the likes of www.thealgarveinfo.com, www.mymallorcainfo.com, www.mytenerifeinfo.com, www.mymaltainfo.com etc..
2009 - 2010 = We decided to consolitdate everything onto 1 single domain, using a sub-domain structure. We used the domain www.mydestinationinfo.com and the subdomains http://marbella.mydestinationinfo.com, http://algarve.mydestinationinfo.com etc.. All old pages were 301 redirected to like for like pages on the new subdomains. We took a 70% drop in traffic and SERPS disappeared for over 6 months. After 9 months we had recovered back to traffic levels and similar rankings to what we had pre-migration. Using this new URL structure, we expanded to 100 destinations and therefore 100 sub-domains.
2011 = In April 2011, having not learnt our lesson from before :(, we undwent another migration. We had secured the domain name www.mydestination.com and had developed a whole new logo and branding. With 100 sub-domains we underwent a migration to the new URL and used a sub-directory folder. So this time www.myalgarveinfo.com had gone to <a></a>http://algarve.mydestinationinfo.com and was now www.mydestination.com/algarve. No content or designs were changed, and again we 301 re-directed pages to like for like pages and with this we even made efforts to ask those linking to us to update their links to use our new URL's.
The problem: The situation we fine ourselves in now is no where near as bad as what happend with our migration in 2009/2010, however, we are still down on traffic and SERPS and it's now been 3 months since the migration. One thing we had identified was that our re-directs where going through a chain of re-directs, rather than pointing straight to the final urls (something which has just been rectified).
I fear that our constant changing of URL's has meant we have lost out in terms of the passing over of link juice from all the old URL's and loss of trust with Google for changing so much. Throughout this period we have grown the content on our site by almost 2x - 3x each year and now have around 100,000 quality pages of unique content (which is produced by locals on the ground in each destination).
I'm hoping that someone in the SEOmoz Community might have some ideas on things we may have slipped up on, or ways in which we can try and recover a little faster and actually get some growth, as opposed to working hard and waiting a while just for another recovery.
Thanks
Neil