I've been looking thoroughly about each constructions, but I haven't been successful about when to use them. Some rules of thumb I've found: * [This forum post](http://www.dailywritingtips.com/forum/showthread.php?52-Prepositions-publish-to-in-on-a-blog&s=2e9ffa3c2e1f237f8703c2f46acef517&p=304#post304) and [this one](http://forum.wordreference.com/showthread.php?t=1406044&p=7122407#post7122407) suggest _publish in_ should be used when the place of publishing is a three-dimensional place and _publish on_ should be used when it's a surface. This makes a bit of sense to me, but does not seem a very academical explanation; whereas there are some cases in which it would be hard to distinguish which kind of place it is. * When the place is virtual, _on_ is used. Example: [Publish on Google Play](http://developer.android.com/distribute/googleplay/publish/index.html) My particular cases are the following: * To publish an application __ [in/on] Google Play * To publish an application __ [in/on] a virtual market Is there a way to identify where to use _publish in_ or _publish on_? Are they mutually exchangeable?