Question: What kind of activity are the niche-themed products Bookchase and San Marco?

Context articles: San Marco Altarpiece
San Marco programme
Porta San Marco, Siena
Bookchase
Italian cruiser San Marco
St Mark's Campanile
San Marco 1
San Marco (board game)
Museo Nazionale di San Marco
St Mark's Basilica

The San Marco Altarpiece (also known as "Madonna and Saints") is a painting by the Italian early Renaissance painter Fra Angelico, housed in the San Marco Museum of Florence, Italy.
 It was commissioned by Cosimo de' Medici the Elder, and was completed sometime between 1438 and 1443.
 In addition to the main panel depicting the enthroned Virgin and Child surrounded by Angels and Saints, there were 9 predella panels accompanying it, narrating the legend of the patron saints, Saints Cosmas and Damian.
 Only the main panel actually remains to be seen in the Convent of San Marco, Florence, Italy, today, along with two predella panels depicting saints which were purchased back for the museum as recently as 2007.
 The "San Marco Altarpiece" is known as one of the best early Renaissance paintings for its employment of metaphor and perspective, Trompe l'oeil, and the intertwining of Dominican religious themes and symbols with contemporary, political messages.
The San Marco programme was an Italian satellite launch programme conducted between the early 1960s and the late 1980s.
 The project resulted in the launch of the first Italian-built satellite, San Marco 1, on December 15, 1964.
 With this launch Italy became the third country in the world to operate its own satellite, after the Soviet Union and the United States San Marco was a collaboration between the Italian Space Research Commission (CRS) (a branch of the National Research Council), led by Luigi Broglio and Edoardo Amaldi, and NASA.
 In total 5 satellites were launched during the programme, all using American Scout rockets.
 The first flew from Wallops Flight Facility with the rest conducted from the San Marco Equatorial Range.
 The last satellite, San Marco-D/L, launched on March 25, 1988.
Porta San Marco is the remnant of one of the gates found the medieval walls of Siena, region of Tuscany, Italy.
 It is found at the start of Via San Marco.
 si trova in fondo a via San Marco.
Bookchase is a board game published by Art Meets Matter.
 Players compete to acquire six small books for their bookshelf.
 They do this by partly by answering multiple-choice questions, partly by visiting special spaces on the board: The Bookshop, The Book Corner, The Library and also by chance events triggered by the turn of an Award or Sentence card.
The Italian cruiser "San Marco" was a "San Giorgio"-class armoured cruiser built for the Royal Italian Navy ("Regia Marina") in the first decade of the 20th century.
 She was the first large Italian ship fitted with steam turbines and the first turbine-powered ship in any navy to have four propeller shafts.
 The ship participated in the Italo-Turkish War of 1911–12, during which time she supported the occupations of Benghazi and Derna, the island of Rhodes, and bombarded the fortifications defending the entrance to the Dardanelles.
 During World War I, "San Marco"' s activities were limited by the threat of Austro-Hungarian submarines, although the ship did participate in the bombardment of Durazzo, Albania in late 1918.
 She played a minor role in the Corfu incident in 1923 and was converted into a target ship in the first half of the 1930s.
 "San Marco" was captured by the Germans when they occupied northern Italy in 1943 and was found sunk at the end of the war.
 The ship was broken up and scrapped in 1949.
St Mark's Campanile (Italian: "Campanile di San Marco" ; Venetian: "Canpanièl de San Marco" ) is the bell tower of St Mark's Basilica in Venice, Italy, located in the Piazza San Marco.
 It is one of the most recognizable symbols of the city.
San Marco 1, also known as San Marco A, was the first Italian satellite, and the first non-Soviet/US spacecraft.
 Built in-house by the Italian Space Research Commission (Italian: "Commissione per le Ricerche Spaziali" , CRS) on behalf of the National Research Council, it was the first of five as part of the Italian-US San Marco programme.
San Marco is a 2001 designer board game by Alan R. Moon and Aaron Weissblum.
 The game is set in Venice, and the title comes from the name of one of the city's districts.
Museo Nazionale di San Marco is an art museum housed in the monumental section of the medieval Dominican friary dedicated to St Mark (San Marco), situated on the present-day Piazza San Marco, in Florence, region of Tuscany, Italy.
The Patriarchal Cathedral Basilica of Saint Mark (Italian: "Basilica Cattedrale Patriarcale di San Marco" ), commonly known as Saint Mark's Basilica (Italian: "Basilica di San Marco" ; Venetian: "Baxéłega de San Marco" ), is the cathedral church of the Roman Catholic Archdiocese of Venice, northern Italy.
 It is the most famous of the city's churches and one of the best known examples of Italo-Byzantine architecture.
 It lies at the eastern end of the Piazza San Marco, adjacent and connected to the Doge's Palace.
 Originally it was the chapel of the Doge, and has only been the city's cathedral since 1807, when it became the seat of the Patriarch of Venice, archbishop of the Roman Catholic Archdiocese of Venice, formerly at San Pietro di Castello.