HP Ad program pays based on the impressions itself - i.e if somebody visits your page and reads your hub, you are rewarded .
The other programs (Google, Amazon and e-bay) expects user action from your page - i.e to earn from Google Adsense somebody has to click the Google Ads in your hub, for Amazon - a transaction has to take place, i.e somebody has to purchase a product by clicking on the amazon product link from your hub ...similar for ebay.
Though Google and Ebay (am not sure of amazon), pay on impressions they are very few to be even taken into account.
So it is normal for a beginner to get earnings from only HP Ad program.
The only way to earn from Google Adsense and Amazon is to write quality hubs which can attract enough Organic traffic (traffic from search engines directly) to enable clicks and purchases.