The same way we all live, we need a quick access to everything, if it is the end of the hall we know we have the bathroom, restroom and our bedroom.
The same way we started to live by it on the web it self, you entering one site and jumping right to the next one in the variety of ways that that same site is offering, from outgoing links to ads on the site.
links is usually the most efficient ways we know on the web just us because we know ads are usually the money interest but the links is usually a partner's links or suggested links by the site we are going from.
Most of the sites we have on the web today is linking other good sites, one of the main reason is for SEO purpose (Search Engine Optimization) because search engines links when you bring credit to other sites we the same relevant content, it's doing great for the site's SERP (Search Engine Results Page).
Sometimes when sites won't linking out of the site, Search Engines would harm the site's SERP, common sense in they're side that says that if a site is strong enough to hold it's viewers it won't be "afraid" to link to it's competitors.
Links from other sites is basically the most heavily power for SEO, any SEO agent will tell you the first thing for making your transfer rate go higher is to bring back links and outgoing links, it shows reliability and reciprocity.
In the back 90's surfers in the net used to try and look over the web to find what ever they needed, what made the internet a very hard place to be it or even worst, after you are actually surfing, you won't find what you need so fast.
That's why Search Engines started to give trust and high PR (Page Rank) for sites that get and take links from outside sites.
The best way to start your own SEO project is to get as much links as you can get, but not just links, try to get links from other homepages, site's archives, site's index and many site's more that actually give away links for back links.
Try to imagine the web as a big highway with allot of exits, as more exits you will get from the road, you can get easy access to everywhere. Allot of site's gives away page as a homepage for an easy access to any good site or to any common site you are surfing on daily basic.
Everyday there's more and more new sites, and not always Search Engines can take charge and control all of them, and not always those sites are good for SEO so they are loosing at the SERP.
The best ways to surf today is by links and by articles about good sites, try to look for new sites and add them your self on indexes so all the world would know the good site you have just found.
