My agency claimed that they were the first to provide this service to clients. I tried this about 2 years ago, and their service are really quite good. And of course, it is really convenient to employers.
But watch out, I also had bad experience on this kind of service from some other agency, they brought the contract for me to sign in my office, but at last they said the maid cannot come. The worst was they didn't refund the service charge and no maid for replace. I lost HK$2500!