Their initial strategy was to automate the crap out of everything. They would try to to keep margins low and part of that was to try to avoid having people talk to non-scaleable customer sales agents.
They did pretty poorly in the beginning until they decided to do a 180 and allow people to have full control in the sales funnel over when they would like to use the website and when to talk to a person (including not using the website the whole way if they so chose).
When they did this sales and profits took off like a rocket.
They then hired enough customer service agents to service demand this way (which was a lot).
I thought it was interesting that they kind of stumbled from 100% automation to a kind of hybrid model that hit an amazing sweet spot.
They did try to reduce certain types of call volume by A/B testing website copy and the like but they always made it super easy to pick up a phone and give a code and instantly talk to someone who could see all their details and never tried to discourage anybody even if doing it online was trivial.