What are some successful tips in finding some potential customers to build a successful email list?

          I have a service that I would like to begin promoting, but I really want this to go the right way from the start. If I can get some assistance in the area of jumpstarting my email list to potential customers, I believe I could finally know where to start searching for the right audience that I believe would be interested in my service. As of right now, I have heard that you really need to build your own email list rather than paying some list building service to send out your ad to a group of prospects that have absolutely no interest at all in what I'm selling and probably never have. That advice to me, makes a lot of common sense, I believe it would be nothing but a big waste of money and precious time. I would rather be the one creating it all anyway for the priceless experience, and maybe here really soon, it would allow me to engage more with a customer on a more personal side of this very, very critical stage of the entire operation. Any advice or direction will be appreciated and greatly valued. Thank you.