Tell Me, Do You Have to Make Things Fun to Attract Volunteers?

I've been witnessing differences in congregations I've visited over the past few months. Some are small, perhaps 150 members.  Some have 400 or 500 members.   One denomination has thousands of members.  Thousands.  What attracts those thousands of people to make the journey once a week or more, depending on involvement, to sit in a space for an hour or so listening to music and message?     It appears that a joyful, playful ambience, with eye-catching items to woo the children and parents, lively music and a warm welcome go a long way to bringing people back. Might it be the same with volunteers?  Is a guarantee of fun the way to bring them back and to keep them involved in the important work of your organization?  What has your experience shown?  How do you keep your volunteers enthusiastic and interested in your projects? Volunteers, what brings you back?  Is it fun that you look forward to having?