I tried installing an app on my phone from the Play Store website, but the install button is greyed out. What could be the problem?
The phone is a Samsung Epic 4G running 4.0
In my case the button was greyed out when I accessed the google play store by using a web search for an app and then following the link to the play store.
If I went to the play store first and then searched for the app, there was no problem.
The solution proposed by Georgi121270 (remove the "gl=US" at the end of the URL address) solved the problem. It seems that the web search found the US version of the play store, whereas when I went directly to the play store, it took me to the version for my local region.