When it comes to ordering books online, the first two companies that come to mind are usually Amazon and the Book Depository. I've been ordering online for the better part of a decade now and have experienced the pros and cons of each retailer so I thought I'd chat about my experiences. This is focused on Amazon UK specifically because that is where I have the most experience.
Oh, and the Book Depository is actually owned by Amazon. The takeover annoyed a lot of people back in 2011 (this article explains things) and it changed the company a lot. All my thoughts on the Book Depository below are from after that merger - there's no point discussing how they used to be (better in some ways, worse in others).
Pros: Amazon sell waaaaaay more than just books. You can order pretty much anything from them.
Cons: If you want a US edition of a US & UK published book, chances are Amazon will not stock it...even if it's available from the US months before the UK version is released. You have to order it from the US site. This also applies if a UK publisher has picked up the series, whether they've scheduled it for release or not.
Pros: Both US and UK options are usually available, which is perfect if you want matching editions or just a particular cover.
Cons: Just books.
Pros: Generally lower than retail. You also have the option of Amazon Marketplace where you can order items that are "fulfilled by Amazon" and third party sellers which can be cheaper.
Cons: Marketplace descriptions can be vastly innaccurate (like new books that are falling apart) and you need to be careful checking the origin of the book as many sellers aren't UK based. Shipping for these items is generally expensive.
Pros: Brilliant for preorders of US paperbacks in particular.
Cons: For UK published and already released books it's hard to find a price that beats Amazon.
Pros: The "Preorder Price Guarentee" which means you get charged the lowest price up to and including release date. If the price drops, so does what you pay but if it increases, you stay where you are.
Cons: Rarely dispatched before release date, especially if you choose the free delivery option.
Pros: Books tend to be dispatched so they arrive as near to the release date as possible. With their delivery method there are no guarentees but in my experience you'll get the book on release day or just before.
Cons: No price guarentee - if that price drops and you want the lower price you have to cancel your original order and place another.
Managing Your AccountAmazon
Pros: You pretty much have full control and are able to change payment and delivery options right up until your order enters the dispatch process. You can cancel orders yourself whenever you need.
Cons: Any problems will be blamed on user error - I had an order switch from free delivery to next day without me touching it. Amazon blamed me and said the original confimation order stating free delivery must have been a glitch.
Pros: It's easy to control what emails you receive from them. You can also adjust your defalt payment and delivery options easily.
Cons: If you need to change anything with an order, you usually need to place a new order and have the previous one cancelled by staff.
Pros: Stuff placed in your basket will stay there forever. You have the option to "save for later".
Cons: Stuff stays in your basket forever - which means if you are anything like me, you end up deleting things or hitting "save for later" over and over whenever you want to order something else.
Pros: You can see estimated dispatch times before you place the order.
Cons: No save for later. Basket gets emptied spontaneously (sometimes things will stay for ages, other times it all disappears if you accidentally close the tab).
Pros: Lots of options - free delivery within the UK, first class, next day delivery and evening delivery. There is also the option for Amazon Prime, a subscription based unlimited next day delivery service.
Cons: Free delivery takes longer to dispatch than any other option and I cancelled my Prime membership when I realised the majority of packages were arriving late. The final straw was being told I had to wait three weeks before a "next day guarenteed" package was classed as lost. Delivery prices can be excessive.
Pros: Free worldwide delivery.
Cons: The dispatch estimates on the website can be inaccurate (I've had "usually dispatched within 48 hours" books take over a week to be dispatched). No other delivery choices so not good if you need something fast.
Pros: It's easily identifiable.
Cons: Packaging is very hit and miss. Sometimes it's too small and the item is crushed, other times it's vastly oversized and the item is damaged from rattling around. It's also usually filled with a bunch of junk flyers.
Pros: Occasionally you get a free bookmark :)
Cons: Books are usually dispatched and packaged separately (bad for the environment and annoying). Packaging can be hit and miss. Junk flyers are occasionally included.
Pros: You have three options - fill out a form on the website (tricky for older orders, especially preorders as it's done by newest date first, so that book you preordered last year is hard to find), call them or have them call you.
Cons: Pretty hit and miss - I've had helpful polite staff but I've also had incredibly rude responses. It's also common to have heavily accented call centre staff who put you on hold a lot and finding their phone number is awkward at best.
Pros: Staff are generally polite, helpful and respond in good time. Rapid responses from their twitter team.
Cons: All customer service is done via email. There is no phone number in case you need/want to talk to a "real person".
Pros: You can file for a return by yourself without having to contact them first.
Cons: Damaged items are very common. The item must be returned AND received by them before you can get a replacement or refund. It's potluck as to which returns label you get - free through the Post Office OR free through a Collect Plus store which you can pay to return through the Post Office (Amazon can refund up to £2.75 but I couldn't find out how you apply for that).
Pros: Brilliant about damaged items! My experience has always been to send photos of the damage and be told to keep the damaged book and take your pick of a full refund or replacement. Damaged items are rare and they always apologise.
Cons: None that I've experienced.
So as you can see there are a lot of pros and cons to both retailers although I do prefer Book Depository on the whole. Their customer service is a lot better than Amazon's and being able to deal with an issue without causing more stress is enough to win my business most of the time. Occasionally I am seduced away by lower prices on Amazon or because I need to order something else and want it delivered with my books.
As a blogger Book Depository also means I can afford to do worldwide giveaways because of their free shipping, and using them is becoming more common which means I can enter more giveaways :)