Almost all web analytics services provide an API for downloading reports and data, but not all allow for the dynamic creation and management of websites to track. Many marketing agencies, web designers, and web hosts need to automatically track visits and pageviews across many of their client sites.
All of these applications have APIs that let you easily add and remove new websites:
Gauges
Gauges was built from the ground up to be a web analytics API. The entire application is built on top of the same RESTful API that is exposed to you as a customer. If you’re looking for real-time metrics like visits and pageviews, look no further. Pricing: Starts at $12/mo
Piwik
Piwik is one of the most popular open source analytics solutions. In addition to basic metrics, Piwik offers goals, e-commerce tracking, and custom variables. Think of it (for better, or for worse) as a replacement for Google Analytics, with an open source licensed version available for those who want to host their own. Pricing: Starts at $49/mo, or self-install the open source version for free
GoSquared
GoSquared is a powerful commercial web analytics service. Beyond just website analytics, GoSquared provides trend analysis and detailed user reporting. The service is well-designed and easy to use. It can also import data in from many third-party systems, such as MailChimp and Shopify. Pricing: Starts at $18/mo, or $68/mo with user reporting
Clicky
Clicky provides a well-rounded analytics tool that provides advanced features, without Google Analytics overwhelming interface. That said, the design of Clicky’s interface lacks polish. Standard Clicky accounts do not allow for API site management, but Clicky White Label allows full API management. Pricing: Starts at $49/mo for white label