It doesn't matter how fast internet connections and server technologies get, there will always be bottlenecks. Either too many people are hitting a website or too many people in your neighborhood are downloading torrents.
A browser plugin that prefetches links or "next websites" on a page based on popularity can highly improve the browsing experience.
There are prefetching clients like fasterfox but they arbitrarily prefetch all links on a given page.
If such a plugin could monitor browsing habits and store them on a "suggestion" server. A service could do statistic calculations about what is the most likely link to be clicked or what website will the user go to next. This can improve the benefit of prefetching. In two words: Intent Crowdsourcing.
Such a plugin can make money for its creator in two ways:
1. selling statistics to websites and web marketers about which pages on the web lead to which pages, essentially a walkthrough or a path guide for the web.
2. Create a suggestion mechanism that will tell users "most users browsed to this page after reading this article", and selling ads in-between the suggestions.
Potentially, this feature can undermine google. A big percentage of Internet searches are performed after some thought was sparked from a previous page. For example, you happen to read about the winter olympics and suddenly you think "let's go on a skiing vacation", you go to google and do a search for "vacation reservation".
This plugin with it's suggestion feature can make the searching part irrelevant. If enough people did that search, you could see the suggestion: "Today, 75 people who read this article searched for 'skiing vacation' on google and clicked on the Third result: snowventures.com".