Final answer:
Local community bulletin boards would be the least profitable place to advertise for a licensed veterinary technician due to their general audience.
Step-by-step explanation:
Of the options provided, local community bulletin boards would likely be the least profitable place to advertise a professional position for a licensed veterinary technician. This is because community bulletin boards typically reach a general audience, which would include many individuals not qualified or interested in such a specific professional role. In contrast, veterinary journals, pet supply stores, and especially online job boards are more targeted mediums, where advertisements are more likely to reach individuals interested in veterinary medicine or those actively seeking employment in the field.