Both Amazon and Google, the two biggest players in the Android app space, have the ability to show “badges” so you can link people directly to your app.  Maybe it doesn’t surprise you, but Google did it better for the Android Market.

Android Market button

UPDATE:  see the most recent Google Play badge guidelines here.  They change periodically:

https://play.google.com/intl/en_us/badges/

Google went so far as to have a badge generator for you, and to host the images.  That’s pretty handy.  You just enter your package name, select the button size, and you now have a snippet of code to paste into your page.

Overall, Google’s solution is pretty slick.

 Amazon Appstore button

Amazon posted in their developer blog about using their badge – but didn’t provide much more useful information besides the three images and some info on using the right link (which unfortunately I think was wrong).  So, what you see above was an image uploaded to my server, and manually linked to my app.  I didn’t find that very difficult, but it did take more time than with the Android Market badge.

Not that there’s really a competition — I’ll probably use both badges when I use them.  Not everyone will take the time to set up an Amazon Appstore badge, though, so Amazon will probably loose out a little from that, and from the lack of sizing options.