If you are missing an entire package, check your tracking information. If the tracking history information indicates that your order has been in the same location for some time (a week and a half), it is likely lost. However, if it keeps moving, even slowly, chances are it will show up at some point.
If your package has not made progress for some time, contact MODG at bookstore@modg.org.
MODG ships bookstore orders in a timely manner; once they are picked up by the USPS, MODG has no control over how fast the box gets to you. Media mail is cheaper but delivery timeframes are slower; Priority mail is more expensive but delivers much more quickly. If you have ordered using Priority shipping and it doesn't arrive in the time you expect, please note that the USPS is responsible for the delay.