I was bidding 10 cents on an [keyword] ad, I was placing (for the last 4 hours) about position 3-4 which was what I was aiming for then I justed checked it again, and it is no where to be seen in the first page, but now half way down the second page. How does this happen? I can't believe all my competing advertisers just in the last hour logged in and upped their bids which knocked me down 8 spots or so. Sorry I am a total newbie to the advertising side of PPC.
The most likely cause is that your ad was not performing. Your position is determined by a function of both your CPC and your CTR. If nobody clicks on your ad, you will move down, even if no other campaigners increase their bids.
I. What time of day was this? II. Did you see new ads appear above you or were the same ads that were below you higher ranking than your own ad? One reason could be you had your ads run at night and some people day part and don't run ads at night, along comes morning and thei ads show up again. Also, the daily budget could be used up then comes 3am PST and the ads kick in again and some are in higher positions than yours but as the day goes and the budgets get used up the ads dissapear. Try and see if you fluctuate in ranking throughout the day and if new ads show up in the mornings and then vanish at night. Hope this helps!