If you run a small call center, or are more of a sole operator, elance might be a great place to advertise. eLance caters to freelancers and small companies who want to sell their services, and YES, you can sell your services abroad to rich Americans who will pay you five times as much as you deserve for your service, until they figure out that they are paying five times as much as you deserve for your service.
But, what if you offer a service that is flexible, considerate, and valuable? You might attract a lot of clients who will stick with you. Remember that promotion is only 10% of the game. RETENTION is the other 90%. If you focus on being available to answer the phone and you care more about solving your clients’ problems than they do (without sounding insane or desperate) then you might get more business than you can handle.
It is easy to post an ad on elance. I personally do not know what the costs (if any) are, but if there is a cost, it will be negligible compared to what you would gain if you got even one bad client. But, what if you got a mediocre client, or even a good one? There are many freelance sites, eLance is one, I recommend trying all of the freelance sites.
My experience in marketing is that you have to be EVERYWHERE that you get a return on your investment. Turn over a rock — there you are! Companies that get work typically either have great exposure or get recommended through word of mouth by an army of satisfied clients. My advice tells me that you should have exposure as well as a very broad referral base for good luck. Get your name out there.