How does Amazon.com probe/ establish network connections?

I've noticed when using new (particularly wireless) networks, when there's trouble connecting ... for any number of reasons ... that navigating to amazon.com sorts out the connection. It's like magic to me, which isn't good!

... having tried a few times to 'crack-it' I've come to a dead end. And it's a feature that I'd like to incorporate in my .net web applications...

I'm left guessing they use some network probe (maybe like .GetIsNetworkAvailable) , but from the behaviour I've observed probably (much) more sophisticated.

The .net web application I'm developing will be used over highly intermittent network connections, so having a feature like this may tremendously help user experience.

It's an open-ended the question that might also feature on other SE areas ... any information will be appreciated. How do they do it?