Should I merge my two sites?

I currently have an old site with approximately 200,000 index pages that gets approximately 40k unique visitors per month, this site is no longer being used since we've built a new site under a new name, so my question would it be best to keep both sites separate and use the old site to cross link with my new site, or should I just 301 redirect all my old URLs to the relevant pages on the new site?

When doing the latter, does my new site inherit SEO value from the old site?

Any advice on this? Thank you.

For me, the bottom line is a commercial question:

Is tampering with the old site worth risking 1/2 Million UV's per year?

You could 301, and you'd get a decent percentage of the 'juice', but there are a million and one things that your new site could be doing differently which will affect the rankings. I've seen major sites 301'd and then lose 90% of their traffic.

Maybe you can just promote the new site everywhere on the old site, and allow natural crossover of traffic. This may even end up giving you two stabs at a monetisable click!

I'm leaning more towards not tampering with the old site. However, it's currently up for discussion with one of the partners who insists that merging is the "morally" proper thing to do, and arguing that the new site will inherit all seo authority from the old site.

I don't suggest you to merge both sites as per statistics given by you!

Slithone said:

I'm leaning more towards not tampering with the old site. However, it's currently up for discussion with one of the partners who insists that merging is the "morally" proper thing to do, and arguing that the new site will inherit all seo authority from the old site.

Click to expand...

The only thing 'morally' correct will be the possible loss of revenue; but it depends on your target audience... We have no idea what sector you're in, (...and I'm not asking. Don't reveal anything here.)