The OP just asked a simple question. S/he didn't say anything about continually adding pages just for the sake of adding pages.
Some sites are static, or nearly so. (What's to add to a metric-converter site?) Others, such as news sites, need fresh pages all the time. And some improve their usefulness to readers every time they add new material. (For an example, if a travel site about Widgetville adds an article about the new Widgetville Eye, which just opened last month, that's an addition that readers will enjoy and learn from.)