Psa
'PSA' stands for Professional Sports Authenticator, and it is a way for collectors and dealers to authenticate sports memorabilia. In the world of sports collecting, there has always been the unfortunate possibility of coming across fakes and forgeries. Now the guesswork of whether or not memorabilia is authentic is taken out of the equation. PSA grading is a fair way for buyers and sellers to reach a consensus as to the value of merchandise.
PSA services are conducted by third parties, as that is the only unbiased way to ensure an item's authenticity. PSA experts are men and women who have been in the industry many years, and can tell the difference between authentic and fake memorabilia items. These third-party graders are paid a flat fee for their services, and there is no 'per value' commission. You can trust the value of PSA-authenticated merchandise.
Primarily, PSA services are used for trading cards. Trading cards, as you know, are valued according to their preservation. Grades of Mint, Near Mint, Excellent, Very Good, and so on determine the price for the consumer. If you're buying online, it makes prudent financial sense to demand PSA card grading before you buy anything.
PSA services exist for all major brands of baseball cards. Topps PSA services are very popular, as are those for Donruss, Fleer, and Upper Deck. There are also PSA graded football cards, hockey cards, basketball cards, you name it. If you look for the PSA logo on the protection sleeve of the trading card, you know it's been authenticated by the pros. If you do not see logo, it isn't a PSA card and could have come from anywhere.