Stamps can be purchased from many places besides the Post Office. For instance, many stores sell stamps at their retail locations, such as grocery stores, bank branches, ATMs, & pharmacies.
You can also get stamps online at Stamps.com.
The following are just some of the places that sell stamps:
Amazon
Albertson's
Bank of America
BJ's
CVS
Duane Reade
King Kullen supermarkets
Kroger
Kwik Trip
Office Depot
OfficeMax
Publix Supermarkets
Quiktrip
Rite-Aid
Safeway
Sams Club
ShopRite
Stamps.com
Staples stores
Stop&Shop
Sugarcreek
TD Bank branches
TOPS Supermarket
Waldbaum's
Walgreens
Walmart
Wegmans
Wells Fargo Bank branches
Wilson Farms