If you make purchases at an Amazon store you have the option to let Amazon ship the items as soon as they are available or grouped together to save postage and handling fees. Shipping and handling is usually not a problem as Amazon will send some items free of charge. For some items though, but it could be a issue. There is another problem that arises if you combine purchases of items that are deliverable and those that are not. This usually happens if you add pre-order items to the purchase. Amazon will bundle these items together if you select to group items in as few shipments as possible which in turn means that you will have to wait for all items until the pre-ordered item arrives.
This still might not be a problem if you do not need the items that can be shipped earlier right away but it could be problematic if the preordered or unavailable item is expected to be available in months. There is one simple rule that helps in that case: Never mix available and unavailable (preorder or otherwise) items in the Amazon store. This might lead to slightly higher shipping and handling costs but it will ensure that the available items will arrive in the usual shipping schedule.
One way to handle this is to add all available items to the cart and complete the purchase before doing the same for the items that are not available at the moment. If you already made the purchase you can still split items in the options of the Amazon order summary for that order. This will usually split the available items from the unavailable ones.
Update: You may also be interested in Amazon Filler items. These can be helpful to cross the free shipment threshold to receive free shipping from Amazon.
Ghacks is a technology news blog that was founded in 2005 by Martin Brinkmann. It has since then become one of the most popular tech news sites on the Internet with five authors and regular contributions from freelance writers.