We have added more servers to deal with traffic increase. Please remember to access the domain names vip.abc.com, www2.abc.com, www3.abc.com and www4.abc.com. "
It is absolutely not necessary to ask members to memorize the additional domain names. Users will be confused about which one to use at a particular time. Just a single domain name "www.abc.com" will be fine and with the use of DNS round robin pointing to several IP addresses, the loading of the servers can be evenly distributed.
Just take a look at www.cnn.com:
[localhost~]# dig www.cnn.com +short