Connectivity: Internet connectivity is either contained in the item itself, or a connected hub, smartphone, or base station. If it's the latter, then the base station will likely be collecting data from an array of sensor-laden objects, and relaying data to the cloud and back.
Processors: Just like any computing device, IOT devices will contain some computing power “under the hood,” if only to be able to parse incoming data and transmit it.
Energy-efficiency: Many devices in the IOT may be difficult, costly, or dangerous to access for charging or battery replacement. One may even think of the Mars Curiosity Rover as an example of such a device. Therefore, they may need to be able to operate for a year or more unattended using a conservative amount of energy or be able to wake up only periodically to relay data.
Cost-effectiveness: Objects that contain sensors may need to be distributed broadly to be useful, as in the case of sensors in food products in supermarkets that would indicate if an item has spoiled. These would need to be relatively inexpensive to purchase and deploy.
Quality and reliability: Some IOT devices will need to operate in harsh environments outdoors and for extended periods of time.
Security: IOT devices may need to relay sensitive or regulated information such as health-related data, so data security will be critical.