Domestically (within the UK, US or Australia) we do use ground services. Currently we don't offer ground/surface shipping for international orders because it's too slow and the majority of people didn't like it (there will be outliers of course). Also, it seems to be less reliable in my experience.
I'm not sure precisely which book you got a quote for, and the price will change based on the size and weight of each book, but let's use
Attack and Defense as an example (you can add it to the cart and enter a postcode etc to verify what I'm telling you). For the sake of discussion, assume that Attack and Defense weighs 256g, with dimensions 18cm x 13cm x 1cm.
A customer can ship that book to Eastern Europe at the following prices and service levels:
Royal Mail Surface Mail: £3.56 - ~$5.64 USD - ~ 5 weeks for delivery
Royal Mail Airmail: £3.62 - ~$5.74 USD - ~ 1 week for delivery
We don't pass on packaging and handling costs (we absorb those in our margins), so the quoted shipping price is exactly what the mail service charges, adjusted with the daily exchange rate if you're using a different currency.
So for a wait of an extra 4 weeks (or more) the customer can save themselves $0.10, or $0.0035 per day waiting. Is that worthwhile? Approximately what proportion of customers do you think would want to do that?
By offering airmail as the cheapest option we make sure that the majority of customers have a good experience. Most people checkout with the cheapest postage option without checking the service levels. They're too busy to research everything and assume that we've made a good postage choice for them.
If we choose surface mail for them in that scenario, a lot of people will be unhappy with the choice when the book hasn't arrived after a month or so. They will think it's been lost and will contact us to ask for a refund or replacement.
Also, for the more expensive postage options, they don't make much sense when sending one book to Europe, but they can start to make sense for larger purchases or products other than books. When shipping domestically or to other parts of the world, there are many more sensible postage options depending on whether a customer wants to add registered/signed for, express or insurance services.
Keep in mind that within the next few months we'll start selling Go boards and other equipment, ranging in price from about $20 to $10,000. Some of the shipping carrier options are predicated on that. We assume that if someone is going to upgrade to a more expensive postage option, they'll think more carefully about what they're paying for. Some people want to get a last minute gift for their son or daughter and the most important thing is that it arrives within 24 or 48 hours, for example.
At some point in the future, if business goes well, we might start storing products in Continental Europe, South America and/or Asia, for shipping by ground in those regions. Currently that would be stretching ourselves too thin.