We read the Capital Advantage privacy policy and came the conclusion that they care less about your grassroots campaign and more about opting you into a "direct mail" campaign (also, known as SPAM)
Will Capitol Advantage use your information for direct mail purposes?
Occasionally, Capitol Advantage may send you messages regarding our products and services that you might be interested in.
It turns out that the "products and services that you might be interested" are those from paid advertisers. Based on complaints and our own experience from previous cap-wiz campaigns, we don't care to promote the service.
Here are some non-commercial resources:
http://www.house.gov/
http://www.senate.gov