Avg CPC prices go up at the end of the month when the # of advertisers

[bostonseo]

Google charges you a higher CPC price at the end of the month if the # of advertisers drop. My proof says they do. Do you typically see a price increase in the last week of the month?

[mike_ppc]

Yes, it usually happens - mainly because there is a special offer ending at the end of the month and some advertisers increase their bids.
About the number of advertisers .. depends very much if it drops from 3 to 2 or from 7 to 6.