Using the online Android Market is fairly straightforward. Apart from some initial hiccups everyone encountered when the Web store first launched, it takes just a few mouse clicks to wirelessly download both paid and free apps without craning over your smartphone screen or straining your peepers.
However, those early frustrations are telling. Scrambling to test the online Market just after it launched, I had no problems selecting apps to download, but several of my first installation attempts failed before they succeeded.
What to do if your online Market apps refuse to download is definitely a concern, particularly if you've just paid good money for an app.
First, have a little patience. People downloading over a 2.5G EDGE connection, for instance, may not see downloads install as quickly as if they were on a Wi-Fi connection. That said, if the installation doesn't start within about 10 seconds, you may have a failed transfer on your hands.
The good news is that your app selection is tied to the same Google account you use on your Android phone.
When in doubt, going to the Settings menu on the Web store will show a list of past purchases. If your app is on that list, but not on your phone, you can download it afresh from the Market app on your phone--without being doubly charged. If your app isn't on the list, just try the installation again from the Web-based Market.