Prefetching pages

Google is integrating pre-fetching of search results. This was a feature already available in many browsers. Personally, I had concerns about this feature: how can you guarantee to save bandwidth? how can you have a consistent analytic on the target sites and avoid to artificially inflate stats? how can you guarantee that ads shown on the target pages are real and not just coming from artificiallly pre-fetched pages that no one is really looking at?