Use the DoubleClick Search API to:
- Upload data about conversions. For example, some customers might search for products online and click on your ad, but then complete the purchase offline. To connect the dots and attribute those offline conversions to an online advertising campaign, upload conversion data to DoubleClick Search.
- Download reporting data for use in your own applications. You can combine the downloaded data with data you already have about your products, customers, and business goals (from a CRM system, for example) to produce big-picture reporting.
If you're unfamiliar with coding practices for Google APIs, see Your First App before starting to code.