Some apps use this to retrieve debug information and send it to the company to help improve the app (eg. Evernote [source]). Couldn't find any information on how Netflix uses the data and can't test but maybe there's a "Send debug information" button or something similar. This, of course, is pure speculation, so you'll have to think "Do I trust this company with my data?"
As to what information is made available by this, you can check this by using aLogcat or the Android SDK and logcat. There's a public Google+ post which describes an example of logcat information.