Starting with v201402 of the AdWords API, all newly created Search and Display Network campaigns will 
automatically be 
Search Network with Display Select campaigns. This means:
  - If you don't specify displaySelectwhen creating a Search and Display Network campaign, it will default totrue, creating a Search Network with Display Select campaign
- If you edit the networkSetting of an existing Search only campaign to target Content Network and do not specify displaySelect, we will upgrade the campaign to Search Network with Display Select by settingdisplaySelecttotrue
- If you create a Search and Display Network campaign or edit the networkSetting of an existing Search only campaign to target Content Network, and specify displaySelectasfalse, you will receive an OPERATION_NOT_PERMITTED_FOR_CAMPAIGN_TYPE error
We encourage you to update your campaigns to Search Network with Display Select by setting the 
displaySelect property to 
true. Starting on 
September 16, 2014, we will start converting all Search and Display Network campaigns to Search Network with Display Select.
Search Network with Display Select uses improved signals and methods of predicting when and where your ads are likely to perform best, and sets a higher bar for when to show them. That means your ads are more likely to be shown to a smaller number of prospective customers, who are more likely to be interested in your offerings.
For more information about creating these types of campaigns, see 
our previous blog post. For more general information about this AdWords feature, please see 
here.
If you have any questions about this change, please contact us on the 
forum or via our 
Google+ page.
- Michael Cloonan, AdWords API Team