Today (and on several previous occasions) I have clicked on google adverts and experienced such an unacceptable delay that I clicked stop and pasted the advertisers url into the address bar.

Makes me wonder how many of my own adverts are so unresponsive that I pay for clicks which the user abandons.

Have google over stretched their systems?

Google's systems were pretty slow over the past two weeks. Many advertisers greatly increase advertising between Thanksgiving through roughly this coming Monday. Some will continue advertising heavily until closer to Christmas.

It is probably pretty difficult to estimate how much that demand will increase. I suspect it was much heavier than it would have been due to the new feature allowing advertisers to test every keyword to find out if it is running.

That feature revealed how rapidly some bids were escalating and at least some advertisers were probably rechecking and adjusting bids far more frequently than they would have otherwise.

Just as rapidly as some bids escalated they have already dropped again. I highly recommend advertisers check their traffic, sales, and advertising costs. If instead of increasing you see that your traffic actually dropped over the last two weeks you may find that you either had significantly increased competition or higher minimums.

Based on what I've seen, demand is likely continuing to drop as I type this. Bids that were under fifty cents before this sudden dizzying climb went to $2, $5, $10, and some wouldn't even run for $10. Many are now back under fifty cents already.