Microsoft has announced that Bing search API will be transitioned to an offering made available on the Windows Azure Marketplace and will not be free anymore.
“With the transition, Bing Search API developers will have access to fresher results, improved relevancy, and more opportunities to monetize their usage of the Search API. To offer these services at scale, we plan to move to a monthly subscription model. Developers can expect subscription pricing to start at approximately $40 (USD) per month for up to 20,000 queries each month.“ [via the announcement email]
The transition will begin in several weeks and will take a few months to complete and till the transition is done, developers will be able to access the API for free.
As a Bing Search API developer, you can expect the transition to involve targeting a new API end point, moderate changes to the request and response schemas, and a new security requirement to authenticate your application key. Developers using approximately 3 to 4 million queries and above can expect to transition through a separate process.
Couple of months back, Google too announced pricing structure for Google Maps API and sites like Wikipedia ended up switching to OpenStreetMap. Given that Bing hasn’t yet defined the market, charging for API seems to be too ambitious to involve developers in the product.