It's worth 15k to have a life and not be tied to the phone and read out every line on the card just so some jackass can bet a $10 5 team parlay.
The accounting is simplified and players will typically bet more frequently since they can access lines and different things like team totals, props, and futures that would be a pain in the ass to conduct over the phone. My guy use to have to spend holidays at the shop answering and would not know where he stood until he tallied the tickets after kickoff. He now has an up to date total of his positions and instead of paying someone to help him answer phones which would be more than 15k, he just automated. He still answers when you call but the call volume is cut by 90% and the $50-100 players all use website but some of his heavy hitters still phone in