The point of increasing difficulty is to s..l..o..w down the collective network hash rate. The frequency of completed rounds should get longer because more shares have to be completed to finish an entire "block" which still only pays say 25 BTC + transaction fee. Most pools reduce the BTC paid "per share" to continue dividing the 25 BTC among the increased number of shares. If you don't increase your miners hash rate or your "collective" hash rate of miners contributing to "your" pool worker - you will see a small reduction in number of shares you earn per given time period as well as a reduction in total BTC earned for each "share" of your work - each time the Network Difficulty increases.
Thank you Dave. I appreciate the detailed response, in helping me better understand this. You're awesome!
