From my experience the home business industry is a great way to tap into a proven system and begin marketing. Be weary of the "automated systems" you will have to funnel lots people into these systems, so just b/c you dont have to talk to people, there are other big hurdles. People will never buy big ticket items with out some level of training and mentorship. The business I found allows me to earn a maximum of $14k per customer, and yes it is not uncommon for them to purchase all of my products at once. While there is a benefit to doing small testing, in the end there may not be a big pay off, and that time and energy could be better harnessed using an already existing model, that has big payouts. I am glad I did what I did, because my ideas are too niche and not mainstream enough. The best thing I could think of is an e-book on how to be a club DJ, but why market to an audience that loves pirating copyrighted material.
Awesome Ideas! But I definitely get savy before you do anything on Google Adwords. Find your market before bringing a product to market. Adwords can be great but find a niche and focus on longtail keywords.