Reading a lot more
I bought this product about 2 months ago and have found that I'm reading for longer periods than before; when books were borrowed from the local library, they would be renewed multiple times, and I still wouldn't have finished them.
One downside is user friendliness: it wasn't as easy to use as a mobile phone and sometimes it is frustrating to highlight exactly the word or text you want to find definition or Wikipedia information.
Having said that, the ability to find the definition, or to search words through the text instantly, in very useful. In a physical book you have to skim through the pages to remember where a certain character or name was mentioned, whereas with the Kindle, you can go straight there.
Battery life is excellent, after two months, I've only now had to recharge after getting to 10% life