Yes, it would most likely be considered as a business since you are doing this to make money which, after all, is the purpose of a business or commercial endeavor. It would be one thing is you were relocting for work or a project and wanted to rent it out while you have been relocated to offset your continuing carrying costs (e.g. HOA fees, utilities, maintenance, taxes, etc.) on the property; that would typically not be considered a business. But AirBnB rentals, where you rent to different people each time, for very short periods of time, and are (we presume) making significantly more than the carrying cost for the unit for the length of time you are renting it (i.e. you are making a profit, not just offsetting costs) would generally be considered running a business.