Actually hubpages does not pay us anything directly. I think you've not read the terms and conditions. Thats alright, i'll explain.
Once we start getting a good traffic to our pages, we earn from the advertisements. So, for that purpose, we should join those sites provided at the "affiliate" site under "my account" page. After that, u've to provide the id no:s from each site to the space provided. DONE!!.
Hubpages will automatically assign those advertisements appearing on your articles to the accounts on respective sites, and that sites will pay you for the clicks or product sales through your page.