It does take traffic from outside of HubPages, yes. Search engine traffic is generally the kind that monetizes best. There are lots of ways to boost your hubs in the search rankings (and lots of hubs about how to do this), but two important parts of this are writing high-quality "evergreen" content (that will still be relevant months or even years from now) and having good backlinks from other sites to your hubs. Make sure you don't spam anyone to get those links.
Over all, I think your best bet is to spend some time reading hubs about how other people have succeeded here. Just type "make money on hubpages" in the search box, and you'll come up with plenty to choose from.