Brief Summary of custom charges:
On any item over £18.00 you need to pay import duty and VAT. For DVDs the duty is set at 2.5% (I think) and VAT is the normal 17.5%. If the actual item(s) in the package comes to over £18.00, you need to pay duty and VAT on the cost of the items plus the postage. If the item(s) are under £18.00 but the value of the postage pushes the total cost of the package to over £18.00 you shouldn't have to pay any customs charges.
Note: the value of the package is calculated using an official chart for currency conversions which is updated monthly (I think) so should the value of the dollar slide dramatically over a month, you still my be charged more than you were expecting as the chart won't have been updated.
While the limit for "Gifts" is £36, inspectors do not accept any package from a company to be a gift - even if a value of £0 is marked on the customs declaration.
What annoys me the most about customs (I don't mind paying the actual tax) is the fact the the Post Office charges £4.00 "admin" fee. This means that the minimum charge is,in effect £4.01 - and all those £4.00 add up over a few orders.
I don't think addresses are targeted by customs inspectors - basically I think they're far to busy for that. I think that they just get to know the format and typical packaging for the specific company and target that. I've been charged a few times for items from PlayUsa - I think customs have just realised here's something they can tax. Amazon.Com parcels are rarely let through customs unchecked.
I know of two places which ship inside the UK and thus do not attract charges:
http://www.loaded247.com - I have used these a few times, including 2 Hercules boxsets and the Lion King Gift Set and haven't been charged any time. However they are rather slow and (like PlayUsa which should be named PlayCanada) they source Canadian goods - which means bi-lingual packaging. Their selection is rather small. Do not use this company for UK releases - they are incredibly slow.
http://www.movietyme.com - I have had a bad expericnce with this company in the past, and have never used them since. But they have since got a new order management system, including order tracking on their website. They typically get goods 1-2 weeks before the US release (they are shipping Brother Bear from the UK now for example) and they offer a choice of US or Canadian covers in some cases (the former being more expensive most often). They have a wider selection than Loaded247. Check out the web in general for service reviews, but I think that the general agreement is the new ordering system is working and problems are fewer and quickly sorted out.
You may also want to try
http://www.cdwow.com which are incredibly fast. Stock changes on their website constantly - when they run out of stocks the item is no longer listed and they tend to just go for the most popular products. I hear customer service is excellent and parcels run a 50/50 chance of detection (but they are cheaper).
I tend to stick with Amazon.Com as their customer service has never let me down once. I've found shipping big orders with a few books tends to avoid customs charges from them. I think the packages are picked up and the handler assumes the contents to be just books based on the weight so lets the parcel through - but this is not guarenteed. Either way, batching discs up into fewer packages means lets £4.00 charges - so you still save money on postage and "admin" fees.
