I set a budget of £3 per day
The clickthrough bar is happy to show me all in one line:
Budget per day £3..........yesterdays costs £3.80
Yesterday it allowed 95 clicks at £.04 - taking me over my daily budget
With no way seemingly to contact anyone at Google and get heard, what can I do to sort this out? It could be potentially disastrous.
The idea behind this overdelivery of clicks above your daily budget is to give your campaigns a little bit more impression on good days (with high search volume), cause there might be other days in the month where you'll not reach your daily budget (because of low search volume, overall or just for your product). This is the idea behind this overdelivery.
But you will not be billed more than your daily budget multiplied by the days your campaigns are running in this month. This is important to know, cause if you run your campaigns only on 15 days in this month, and you have an overdelivery of 10-20% each day, the maximum amount you have to pay will be your daily budget x 15 days (and not x 30 days for the entire month). So like sem4u wrote, all hits above your daily budget multiplied by the days the campaigns run is totally free traffic.