Why would we do anything we are not passionate about? Big joke, we know as many people spend endless hours a week doing things that we do not enjoy. The point is, when we have a choice we want to do something that either we are passionate about or that we know with help us grow as individuals or a community.
Volunteer Managers have a difficult task of recruiting people to do something that may or may not be exciting to them. This is where communication plays a huge role. To get a volunteer you need them to buy into the overall goal rather than just the task. Tools, like ivolunteer.com, can assist you with your mission by providing additional communication functions to reach your audience. You can send out a request to volunteer with the organizational message, online sign up can set expectations, and follow up e-mails is great for showing how their donation of time helped achieve success.