Computer Training Success

I am an IT Trainer at our company (500 people in house and another 500+ at warehouse locations and field staff). Currently we are targeting our staff at our corporate office. I offer computer training every day and each session typically takes 30-45 minutes on one specific topic, for example, Excel Macros.
I typically have 4-5 people in each session, but I would like to have more attend. I have some people here that want to learn more about computers because the love to learn and also realize it will save them time. The others say they don’t have time.
I am working with our web developers to create a site that has e-learning and list the classes they can register that I have scheduled. I will include a point system and as they accumulate points for attending they can choose prizes. I am also going to have a contest that each class you attend you will be entered to win a printer. Finally, I email newsletter with tips and also have a question with a give away as well.
Any ideas
I am trying to get more people to attend classes or want to attend. What can I do to make it more appealing, marketing that will interest them, etc?

Roseanna