The 4 old sites will be shut down after around 4 months, the domain names for these sites will NOT be available to us (it's a long story) and so cannot be made to redirect to the new site.
Many other sites link to the 4 old domain names, what is the easiest way of informing them that they should use the new domain name?
I'm hoping there's an automatic way of doing that (but I doubt it).
Thanks,
Mike
If it were my assignment my strategy would be to minimize the effort by first determining which sites, if any, are either a) sending significant traffic; or, b) hold some real potential to do so (some level of authority and commitment to quality). In other words, to minimize wasted time cherry pick referrers and then send personalized emails.
General consensus is that the level of devotion to updating outbound links is on par with the linker's devotion to sending you traffic OR the linker's habit of visiting your website (because it's a quality or interesting site).