If you're developing mobile websites or native apps, you'd better take a closer look at the fine print. Some APIs, including one from Amazon, specifically exclude mobile applications. And there's not much explanation--or logic--behind the exclusions.
The extremely popular Amazon Product Advertising API (our Amazon eCommerce API profile) makes it very clear: no mobile. Along with the usual trademark and rate limit criteria in the Amazon license agreement is this line:
4(e): You will not, without our express prior written approval, use any Product Advertising Content on or in connection with any site or application designed or intended for use with a mobile phone or other handheld device.
Amazon is one of the last I would expect to be restrictive with developers. The company was a trailblazer with its open API, so it long ago came to the realization that developers are good for business. I'd expect the fact to remain when going mobile.
We saw something similar recently from Zappos, the popular shoe site owned by Amazon. When it launched the Zappos API (our Zappos API profile), mobile was off limits without explanation. Then Zappos came to its senses and developers can now create mobile applications using the platform.
It's difficult to guess at the rationale for excluding an up-and-coming channel with a ton of developer interest. There are hints, perhaps, in the terms of service from Eventful, an event discovery platform:
Appendix A. For other applications intended to be used on other kinds of devices including mobile devices, mobile phone, auto applications, etc.: Please contact email@example.com for licensing information
Is it because providers see money in mobile? It's difficult to see this as very different from websites. There's money in the web, after all. Many API providers allow only non-commercial use of their platforms. The same would work for mobile, without the need to single it out.
Hat tip: Clay Loveless