Even in the "documents" case of the web there can be pretty significant savings if users tend to visit more than one page and they share some amount of structure.
On the first entry to the site you trigger the load of an external dictionary that contains the common parts of the HTML across the site and then future document loads can be delta-compressed against the dictionary, effectively delivering just the page-specific bits.
You need to amortize the cost of loading the dictionary across the other page loads but it's usually pretty compelling once users visit more than 2-3 pages.
On the first entry to the site you trigger the load of an external dictionary that contains the common parts of the HTML across the site and then future document loads can be delta-compressed against the dictionary, effectively delivering just the page-specific bits.
You need to amortize the cost of loading the dictionary across the other page loads but it's usually pretty compelling once users visit more than 2-3 pages.