<% @brand_promotions.each_with_index do |index, brand_promotion| %>
        <% if (index % 4) == 0 %>
          <div class="row">
        <% end %>
        <div class="col-3">
          Column <%= index %>
        </div>
        <% if (index % 4) == 0 %>
          </div>
        <% end %>
<% end %>

<% @brand_promotions.each_with_index do |brand_promotion, index| %>