Titanic was built to make money but not on the backs of immigrants as some claim. Instead they were designed to make money from wealthy passengers who would travel both ways. Second class was designed for tourists and professionals who traveled less often but wanted the comforts such a ship offered. And finally you had third class (steerage back then) who paid the smallest fare but proportionally were the largest in numbers. However despite their numbers, they were a smaller revenue generator compared to first class passengers.
Joseph Mortati in Collision Course:How Good Business Decisions Sank the Titanic and Why refutes the standard thinking by going through the concept of the new White Star ships and how they were designed to make money. Cunard, which had the faster ships of the day that broke records, sacrificed speed for comfort. The line was also subsidized by the British government to prevent it from being bought out by a foreign entity. That gave them a 2-1 advantage over White Star. They had speed and government backing. Ismay had to come up with a way to compete that would make money. Competing on speed would be difficult and expensive. They could still market to immigrants seeking to cross over to United States but they knew it was a diminishing trade over time.
Focusing on repeat travelers then became important. And not just any repeat travelers but ones who were very wealthy and willing to pay extra for comfort. They could charge higher tickets for them and provide amenities a hotel on land would provide. It was a daring and bold plan that hinged on getting the wealthy to buy tickets. It required a marketing campaign to convince them that ships like Olympic or Titanic were the ships to be on and be seen on. What Mortati found was that Olympic compared to Lusitania would make 40% more per round trip because of those higher ticket prices. And while immigrants still comprised 50% of passengers aboard, revenue from them was 20%. Which means 80% came from first and second class passengers and mostly from first class.
Now that debunks the myth. Had Olympic, Titanic, or Brittanic been built to make lots of money from immigrants, the proportions would have been very different. Instead you would have third class being the significant revenue generator and first and second class bringing around 20% combined of the total revenue.
Mortati, Joseph Collision Course – How Good Business Decisions Sank the Titanic and Why (2013, Amazon Kindle Edition)