No changes to quality scores, competitive landscape, notices on the account or anything - just complete zero.

Have you hit a budget constraint?

That's what the system says I've just discovered - but daily budgets are $3K+ and with 0 clicks we've not spent anything (nor do we normally get near the $3K either!)... is there another account-wide-monthly budget amount somewhere I don't know about?

I just called them now they're awake.. all they'll tell me is that the account is under review and it might take a few hours or a few days before they get back to me, they don't know. I can't think of any other supplier who takes so much money off us that has that kind of support.

is there another account-wide-monthly budget amount somewhere I don't know about?

It may depend on your payment method and the structure of your agreement - but I have two budgets - an overall account budget (which is set-up by Google) and a daily budget (which is controlled by me within the account).

"account is under review and it might take a few hours or a few days"

Yes . This happens to fairy new accounts and also to some old ones as they ramp up..

You have no option but to wait..

We're a very old one ramping up over the last 4 months. Apparently the 'under review' bit is finished now, but they don't know why it's not back online. So blood pressure down a few points but not yet normal...

I wonder if my leasing company will turn up one night and take all our gear away to review our account for some indeterminate period too..

Just a note for future paranoia searches - they switched our site back on after 35 hours (it should've been 24 but someone screwed up apparently!). The good news - performance across all our primary campaigns has noticeably improved since we came back on. I can't nail anything down just yet so it might just be happy co-incidence with April, but cost per conversion is right down, CPC is down, impressions are up, CTR is up. All else remains as was.

So maybe it's not all bad getting a review :)