netmeg - 6:59 pm on Feb 1, 2013 (gmt 0)
I would add to the above - check out who has replaced you, who's now getting your traffic? Are they doing something unique and wonderful that you're not? Ask everyone associated with the site to write down five reasons why they think your site/company DESERVES to get your traffic back - then read over all those reasons, and if they're all valid, make sure they're well represented on the site.
I can't tell you how many times site owners have called me up and said "of *course* we're the authority in the industry" and either they weren't, or they were, but they weren't reflecting it on their site.
Get some objective third party opinions on that site. Sign up for one of those testing services (you can do it for as little as $30 a session) where someone performs some task on your site, like looking something up or trying to complete a transaction and provides you with a running commentary so you can view the site how the users view it (I did that once with a client - we got a screen cam video back, and my client said "I kept wanting to move his mouse for him to the right spot" - that told us we needed to work on the navigation)