If their competitors were writing their applications in C++ or Perl, it probably would have made a noticeable difference to their iteration speed. Writing a web application in C++ (especially in 1995) would not have been too efficient.

I'm sure that they had a good understanding of their customers, but the language had to have made a difference as well. These days, we're writing web apps in languages like JavaScript and Ruby, not C++, so the difference would be a lot less significant.