Products, including assistive and accessible technologies, do not exist in isolation. They are all part of rich product ecosystems; they inhabit specific niches of economics, functionality, and technology, and they interact with other products. The concept of product ecosystem goes beyond technological interoperability. For accessibility to advance, we must understand more about the interactions among products. This paper sketches an explanatory approach that may be useful in understanding how accessible technologies thrive, survive, or fail within their ecosystems.