What is a proxy service? A proxy service, sometimes called a "deputy", is a company or a person located in Japan that helps you buy items on Yahoo Auctions Japan. The proxy service acts as the middle man and handles the Japanese side of the transaction and collects a fee for services. The Buyer (you) finds an item and places a bid, and then the proxy takes over from there. They communicate with the Seller, make the payment, receive the item, then forward it to you overseas.
Proxy services started a few years ago in response to foreigner's desire to purchase on Yahoo Auctions. In the end the Buyer has to take a couple of extra steps and pay a little more, but it eliminates all of the hurdles to buying from Yahoo Auctions and in the end he'll probably save some money since many items sell for less on Yahoo Auctions than they do on eBay.
From the Seller's perspective he's working with a regular Japanese buyer. The proxy company communicates with him in Japanese. They make a payment to his Japanese bank account. They use a Japanese address for shipping. They leave feedback for the Seller (usually). If a proxy has done its job well then the Seller should have no idea that he's working with a middle man and not the actual buyer directly.
All proxy companies work on a deposit system; you have to make a deposit before you're allowed to bid. Usually your deposit is a percentage of your maximum bid amount, for example 50%. If you deposit $100 then you can bid up to $200. If you deposit $200 then you can bid up to $400. Each company has their own system but they all require some kind of deposit before you're allwed to bid.
Different companies, different systems...
There are varying degrees of sophistication to each proxy company. All of them have Yahoo Auction accounts (sometimes multiple) that they use to place bids for their customers. The very basic proxy services require that you send an email to them with a link to the item and your maximum bid amount. The proxy then manually places the bid for you from their Yahoo Auctions account.
Recently proxies have been able to offer "real time bidding" meaning your bid can be made by the Buyer through the proxy's website. You log in to the proxy website, enter in the link and bid amount, and their system will automatically place the bid for you through one of their Yahoo Accounts. Other proxy companis offer to set you up on your own Yahoo Auctions account which means you can do your own direct bidding and the proxy will access your account and handle everything for you after.
In the end it's up to you to decide which company/method is best for you. Automation is convenient but it's usually found only at the larger proxy houses that handle a lot of bids so getting any kind of special attention is difficult. The slower, more basic proxies can't offer real time bidding but you usually get access to a real person who can answer questions or give some extra help.
Other Differences
Beyond just the core function as a bidding/receiving company, each proxy has their own system for handling the items. Some have online accounts where you can check your status, some don't. Some offer to hold items so you can combine shipping for longer times than others. Some ship directly from Japan to you, others send items in bulk to the US and then ship from there. The fee system for each is different and can lead to different costs for the same items. Some charge a handling fee for shipping, others don't. Some will lower the value of the package to help foreign Buyers save on import taxes, others won't. In the end there's a lot of information you need to check before deciding which one is best for you.
