A snap-in card top riser is provided having a riser and a display module. The riser has a hook profile that is adapted to be received into a channel on the display module so that the riser is secured to the display module in a manner that restricts removal of the riser from the display module. The channel has one or more tabs that are configured to cause the hook profile to compress while the tabs are engaging with the hook profile. A modular display tower is also provided that includes a base and one or more vertical display portions that are configurable to display different types of cards, items, and merchandise. The vertical display portions may interchangeably include curved display modules that receive one or more risers, or flat display portions, and the vertical display portions may be joined at respective edges with a bridge coupling.