Can I limit the amount I spend per day?

Yes you can.

You can set a Daily Budget, this will ensure you will not spend more than you wish a day.

It requires a monetary value, so if your campaign was Worldwide at $1 CPM and you wanted to get 100 visitors a day, you would set your Daily Budget to $0.10

Please do not confuse a Daily Budget with repeat payment. The advertising payments are manually made by yourself and we cannot automatically take any money from your PayPal account.

Setting a Daily Budget also ensures your traffic is evenly spread out over 24 hours and not sent in a very short time period.

To set the Daily Budget in your account, please click on the little wrench icon by the campaign. Then enter a figure next to Daily Budget: and finally, click the Update button.

The Daily Budget is set to GMT timezone, so the best way to use is to set it once a day to make sure that traffic will be sent as evenly as possible.