Some might consider to be unimportant,what is affixed on the parcel when You order a book or
a collectible or anything large heavy and expensive in mail...
And in most cases You can see the postal label,sticker or ATM meter of vending machine showing You
the postage paid alike USPS $21.95, Posta Italiana €15.60 or Royal Mail £20.00 ...
And it means that this amount was spent completely and forever...
But why? Because there were no stamps affixed for there amounts, and all stamps,especially of
high face value, even in used condition do cost some real money among philatelists, while modern (not the old ones!)
meter-marks or postage paid labels cost about nothing...
That is why, request from sender,the item delivery to be paid with postal stamps,if possible.
Why not to take such a pleasant postage discount as 10-20-30% of delivery charge, depending on stamps and
fortune...  ? For postage paid score of $1000.- it is $100-300 back into Your pocket!
Same way, being a seller,do affix to your buyers nice stamps (when You can) and pay customer's attention to their
value as used ones. This way You may cause the birth of more collectors in the world.
Also remember that such philatelic wonders as blocks, coupons, tete-beche, semi-postals, high face value stamps,
highly wanted commemorative topicals, marginals are valued higher than average definitives.
Be creative!