Final answer:
The scenario described is an example of a short-term, unintended media effect where a toy sells out quickly as a result of a television ad campaign.
Step-by-step explanation:
The given scenario of a television ad campaign for a new toy starting in late October and big box retailers selling out of the toy within weeks as parents prepare for the holidays is an example of a short-term, unintended media effect. The intention of the ad campaign was to promote the toy and generate sales, but the outcome of the toy selling out quickly was not necessarily planned. This exemplifies how the media can have immediate and unintended impacts on consumer behavior.