Some make a little, some a lot. Everyone starts out with little, and those that have a plan eventually can make quite a bit -- several hundred a month, to even thousands a month.
To get to making money you need:
1) LOTS of Hubs (100 absolute minimum, many more better).
2) Hubs are commercial (product or money making related).
3) Hubs have many links from outside HubPages.
See my profile and look for the Courtney link for more details.