One of my favorite books is Made to Stick: Why Some Ideas Survive and Others Die by Chip and Dan Heath.   In this book the authors teach you how to create sticky ideas by using the SUCCESs model:

Ambient Insight report states that the worldwide market for 2009 self-paced E-Learning Market and services grew to $27.1 billion. The international demand for online learning is growing by 12.8% and revenues will reach $49.6 billion by 2014.

North America will be the top buying region in the 2009-2014 timeframe.   Asia will be the fastest growing region, however with a growth rate over 33%.   By 2014 Asia will overtake Western Europe as the 2nd largest market for E-Learning.   

Using a Dog Clicker to improve your E-learning...who would've thunk it.   When recording audio have a dog clicker in hand.  When you make a mistake click on it.  The sharp click is easy to spot in the sound editor and makes it a lot easier to edit out the mistake.