IMO it is a complete scam.
Case in point - lets look at a BIN t206 on ebay right now:
http://www.ebay.co.uk/itm/FRED-JACKL...item3f3f971300
Priced at $40.00
You won't be able to see this logging in from the US but the other costs are:
Shipping to the UK is $13.30
The GSP adds another $12.61 BUT - this is only an estimate. You DO NOT get to see the correct price until you check out. It is often higher.
Note - the GSP is listed with the words IMPORT CHARGES.
Now this is where things get more interesting - current UK law states that any purchases less than £28.00 = $43.87 at current rates are exempt from Import Duties (shipping costs are not included in purchase price calculation). Import Duty would start be based on every penny above £28.00 at 20% (yes 20%).
Additionally, books, magazines, newspapers, basically any written material is EXEMPT by law from Import Duty into the UK. BUT such items that are listed by US sellers that sign up to GSP do incur the GSP or Import Duty charge.
Please understand I don't mind paying Import Duty where expected but would rather pay direct to the UK government than ebay and its partner in GSP - Pitney Bowes.
I bought a couple of items from sellers using GSP but now simply refuse to even look at thier listings.
Martin Parker