Offers is a unique HeyJinni feature. It is not available for products on the marketplace, but rather for offering time-limited (e.g. black Friday) discounted etc., products/services on your business Page. In that sense, it is an additional but unique method of service/product lead generation for businesses using or not using HeyJinni marketplace. Offers is most effective when combined with HeyJinni marketplace and ads.
In order to use the Offers feature you must have a HeyJinni (business) Page. It does not cost anything to create anything on HeyJinni, and the same applies to Pages.