Value of clicks falls away toward the end of the month?

Do any of you find this? I've noticed that, even in the best of months, in the last couple of days the clicks are worth less. Is this because Adwords budgets run out in the last few days of the month?

 

It's normal...Advertisers budgets are spent at this time of the month...

 

That's not very true sometimes my cpc get's very high at end of the month's

 

Maybe it's just something i'm imagining, but the spent budgets thing seems to make sense. I've seen it again this month. In the last few days the click value falls to about 50% of what it had been earlier. Traffic and clicks remaining fairly level.

 

Ya, same with me,,,