The mounting system includes at least one first crossbar with a first end cavity and a second end cavity, and a first support bracket insertable into the first end cavity of the first crossbar. The first support bracket includes a first engaging structure, a second support bracket insertable into the second end cavity of the first crossbar. The second support bracket includes a second engaging structure, the first and second engaging structures configured to attach to respective first and second columns of a consumer product display. More than one vertical upright is connectable to the at least one first crossbar, where the more than one vertical upright includes a third engaging structure. The method includes connecting the vertical uprights to the crossbars, inserting support brackets in the first crossbar, attaching the support brackets to a column of a consumer product display and connecting shelves to the vertical uprights.