You need to be very careful to check all of the various offers available prior to booking.
If you have a Mastercard, you can get 11% off the base rate on Expedia Rate bookings (and 12% off Agoda bookings - it still works) using the following link -
www.mastercard.com.au
You cannot combine the various Expedia offers and the base rates may not be the same (before any member pricing, discounts and/or points promos).
Although I normally use Agoda for most hotel bookings (as they are generally cheaper overall), I did make an Expedia booking yesterday for a hotel in Germany using the Mastercard link above.
Reviewing the pricing for the same hotel I booked yesterday using both the Mastercard and the VFF links this morning, the VFF base hotel rate was ~11% more expensive than the Mastercard base rate (before any discount). Once the 11% Mastercard discount was included, the VFF rate was ~19% more expensive than the Mastercard rate. There is also another future ~1.2% discount in Expedia Rewards using the Mastercard rate.
To be fair, this example did appear to be the exception rather than the rule. The base rates (before any discount) for most hotels in the area did appear to be the same using either of the Mastercard and the VFF links. Expedia may have a special deal with this particular hotel and this is why it was cheaper when booking direct and also cheaper than booking with Agoda.
Agoda easily won all my other (non Accor) hotel bookings for the trip...