Conversation so far:
What is the background of Tosca?
In the early 1880s, the French playwright Victorien Sardou began a collaboration on Tosca with actress Sarah Bernhardt, whom he provided with a series of historical melodramas.
Did Sarah Bernhardt play a role in Tosca?
Sarah Bernhardt starred in La Tosca throughout Europe
Where did Sarah Bernhardt and Victorien Sardou take La Tosca in Europe?
Tosca premiered in Paris, with more than 3,000 performances in France alone. Tosca had played in both Milan and Turin, as well as across Europe.
How was the play Tosca received?
Tosca was an outstanding success, with more than 3,000 performances in France alone

Question: What made it so popular?
Self-contained rewrite: What made the play Tosca so popular?