Amazon tried to do a big media push about their new Silk browser that uses the cloud to accelerate the data the user is getting. But according to the review from Anandtech and a few others I've seen, the Silk browser is actually slower than most other mobile browsers.
The idea behind Silk was to compress your data on their servers, and then deliver you a different, smaller file, that would help you save some data and browse faster. Apparently, it does save data, but since the Kindle Fire is wi-fi only, it all seems pretty pointless. Not to mention that it's also slower than a normal browser. The reason for that is that it probably takes too long for the files to be redirected to Amazon and back, and then to convert them. That whole process can end up taking more time than just browsing normally.
So why did Amazon did it then? My guess is it has less to do with saving you data or time, and more to do with them having access to your data (although anonymously, or so they claim). Browsers like Opera Mini save up to 90% data when compressing pages, and the sites load up to 3x faster. Initially, I thought Amazon would at least be competitive to that, but it doesn't seem like it's competitive in either.
What's funny is that a big part of the web started claiming how amazing the Silk browser is, mostly by being influenced by Amazon's brilliant PR and naming of the browser. Silk signifies that the browser is smooth and fast, and that's exactly how many bloggers painted it in their headlines and posts, even though nobody had used it. This speaks how important the power of marketing is when you do it right.
Will this affect Amazon too much? Probably not. Their target market won't even know about this, and if they do, they can just use the browser without the accelerated feature. That, however, won't make Amazon very happy because they were hoping to collect information about their users' browsing behavior, and use it for their e-commerce recommendation engine to know what people are looking for online.