A server computer system, comprises a processor; a communications module coupled to the processor; and a memory coupled to the processor, the memory storing instructions that, when executed, configure the processor to receive, via the communications module and from a third party server computer system, a session handoff that includes session definition data identifying two or more items; provide, via the communications module and to a client device, a user interface for defining instructions based on the session definition data; receive, via the communications module and from the client device, the instructions defining at least one threshold associated with the two or more items; and perform an operation in accordance with the instructions defining the at least one threshold.