We recently migrated a clients domain from domainA.com to domainB.com.
If you are familiar with search engines and indexing, migrated domains that do not have proper 301 redirects pointing from the old domain to the new will cause the new domain to miss a lot of search engine traffic. The new domain will in fact have to start all over again and get re-indexed by search engines which can take months.
How do you implement a global HTTP 301 redirect?
In ASP.NET, it requires editing the global.asax's application_beginrequest event...