You might have looked at your campaign and noticed it is highlighted in yellow and says "Paused". Below are a few reasons why your campaign may no longer be live, and is showing as paused:
1) Your campaign has exhausted its daily budget and is currently paused automatically until the next day. If you want to continue running your campaign, you'll need to increase the daily budget amount.
2) You may not have enough funds available in your account. In some cases, advertisers have several campaigns running with varying budgets. Please make sure you have enough funds available in order to meet the budget for each campaign. If not, you will want to add/top off funds to your account to reactivate your campaigns.
3) In some cases there is just enough money in your account to cover your campaign budgets. We may require you to add additional funds to the account for any unforeseen charges to your account. Generally if you have more than 10% of whats allotted for your campaign budgets, you should not experience any interruptions in traffic flow.
If you are still unsure why your campaign is showing as paused, please contact your sales manager or speak to one of our live support operators.