Are you talking about live streaming of services? Aside from the technical issues, and possibly legal ones if using a commercial video chat service, many churches (besides MCCs) don't do them for fear that they'll cut into their attendance, not to mention donations into the church collection basket.
Yet I know one very small church here that has tried it, as a way to expand their attendance, which was often zero. To my knowledge it hasn't helped them.
More common is to record services, and especially sermons, to view online afterwards. That can act as an "informercial" or "sampler" that encourages new attendees. If you want to try that, embedded in your church's website, I can put you in touch with our local MCC, which does that.
See the video on the top of the right sidebar at our MCC's website:http://sunshinecathedral.org