We sometimes offer discounts to selected customers, based on the currently running promos, holidays, special offers, etc. In certain cases, you purchase a so-called intro-offer: a subscription that goes with a discount for the first payment, and the usual price afterward.
Discounts normally apply to the first transaction only, so all consequent renewals happen at the full price.
You can view a total breakdown of charges for the products you bought in your Dancebit Web Profile.