First, everyone knows what a bitcoin and a satoshi are. No one understands "bits". I had to look it up myself and mentally convert everything to make sense of the pricing on the site. But that pales in comparison to the second problem:
Bits is becoming a more known term in the Bitcoin world for measuring micro transactions, and for me has the same notoriety as mBTC. However it would be nice to have some sort of currency conversion when displaying the amount sent/recieved, I agree.
You are using a period instead of a comma in all your "bits" prices. Now, maybe I'm wrong and you are selling Grand Theft Auto for less than two US pennies. But it seems rather more likely that you are displaying to American customers all your pricing using the foreign convention of a period where Americans use commas.
The way that currency is preferably displayed depends heavily on the person interpreting it. If the developers behind XAPO had been told to use full-stops/periods when displaying large numbers, that is likely what they will do. For example, I had always written larger numbers using a comma, however I was told to stop doing this as a student as it can cause problems if the reader would misinterpret it as a decimal point. I was told to replace it with a space within my numbers (IE $30,000 to $30 000), however I believe this can also be somewhat confusing. Once again, perhaps showing conversion to Satoshi/BTC would help significantly.
If I'm wrong in my interpretation and you really are selling all those games for a few pennies each, more power too you. But otherwise, you may want to fix or at least clarify this pronto.
XAPO is a payment processor AFAIK; they do not sell games. Perhaps you should notify the service selling the games of the price discrepancies.