<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by Tango:
These are taxes that they are passing on to you becuase they are now required to pay taxes (as a third party) on any miles bought from the airlines.</font>
This is just a cost of providing the points and should be part of the quoted daily charge but, as we've seen so many times in the USA (can you say "energy surcharge"?), companies love quoting a low rate and then adding anything they can think of on to the bill later.
I've noticed that this particular tax doesn't seem to apply to overseas FF schemes, which is nice. (Gee, do I want to earn 250 miles on a U.S. airline and pay tax on it, or 700 miles on Qantas with no tax? I wonder!)