I've upped my keyword bids on several keywords that see some traffic to the point where Google says I should be in the top 1-3 listings....I'm seeing my ads on search result pages in good positioning....but still I'm not seeing any impressions, not for about 15 hours actually. How often does Adwords update? Is there something else I could be missing?
Every few hours. Double check and make sure you're looking at the right date range - I've seen that trip people up before.