People aren't signing up or giving money? Maybe your call to action isn't prominent enough Or maybe it's not crystal clear. Or maybe you're not asking for the right thing. Put your materials, web site or appeals in front of you and ask yourself: Is my call to action...
Ask for one concrete action. Telling people to click on a button to donate now is better than asking them to participate in a fundraising campaign. Asking parents to read to their children for 15 minutes every night is better than asking them to support reading readiness. Specific actions are easier to do - and harder to decline.
For most people, if the action doesn't seem doable, they won't do it. "Save the earth" does not sound like something any one person can do easily. Make the step you're requesting small and easy, such as "put your plastic in your curbside recycling bin on Tuesdays". You can build up to bigger requests once you have initial momentum of compliance.
A good test of whether your call to action is simple and specific enough is to ask if it would be possible to film the audience taking the action you desire. If you don't have a simple visual, your audience won't. I can't picture myself as being against a legislative bill, but I can see myself writing to a member of Congress via an email form.
Make sure what you're asking for is an action that, if people did it, would significantly and immediately advance your marketing goals and your mission. If your call to action will only "raise awareness," take it one step further. We want people to DO something that will truly make a difference for your organization. Are you asking for the right thing? The Truth Campaign got teens to quit smoking by asking them to rebel and act out more than asking them not to smoke. PSI's YouthAIDS launched a guerrilla marketing campaign that asked people to put "kick me" signs on each other. It's an unusual call to action and an intriguing application of these principles.