1. A computer-implemented method for providing an interactive seat map showing locations of available tickets in an event venue, the method comprising: receiving, at a client computer device from a network-based computer system, a base map illustrating locations of sections within the event venue; receiving, at the client computer device from the network-based computer system, a predefined coded image map for building a map overlay, the predefined coded image map comprising predetermined polygon coordinates for each section depicted in the base map; receiving, at the client computer device from the network-based computer system, an inventory for an event at the event venue, the inventory providing, for each section, section data that includes available tickets for each section within the event venue; displaying, at the client computer device, the interactive seat map by loading the base map and by building the map overlay on top of the base map at the client device using the predefined coded image map so that each polygon of the map overlay aligns with a respective section of the base map; displaying, at the client computer device, blocks of ticket listings for a plurality of the sections next to the interactive seat map prior to receiving a selection via the map overlay, each block of ticket listings comprising available tickets for an associated section within the event venue from sellers associated with a plurality of online marketplace services; determining, at the client computer device, a plurality of characteristics for each polygon of the map overlay based on matching a section identifier of each section in the event venue with the received section data corresponding to each polygon of the map overlay, the plurality of characteristics for each polygon comprising a fill color, a stroke color, and a transparency to apply to each polygon of the map overlay; applying, at the client computer device, the plurality of characteristics determined for each polygon to each polygon of the map overlay; linking, at the client computer device, each polygon of the map overlay having available tickets to a corresponding block of displayed ticket listings associated with a section of a respective polygon, the block of ticket listings for each section being displayed among the blocks of ticket listings for each of the other sections having available tickets next to the interactive seat map; receiving, at the client computer device, a selection of a section from a user via the map overlay; and redirecting, using an established link between a polygon and a block of ticket listings associated with the selected section, a display of the client computer device to present the block of ticket listings for the selected section, the block of ticket listings already being situated among the blocks of ticket listings next to the interactive seat map.