Did a little experimenting this week. Barely broke even with increased investment in adwords dollars for one set of keywords. However, continued to slightly increase adword investment on my best set of keywords and continued to see increase in adsense income. For the week I spent $90.00 in adwords and saw adsense income of $210.00. Live and learn.
Next week I am putting all adwords dollars into my best set of keywords and hope to get back to getting a return of 3x the investment in adsense dollars.