That the provider is corresponding/flirting/building a rapport with many simultaneously. You are only corresponding with her.
Most providers expect to spend a reasonable amount of time communicating with their clients before meeting. Reasonable is the key word.
The girlfriend experience is just a fantasy-- you should keep that in mind. Your real girlfriend/romantic interest would have all the time in the world to get to know you and flirt back and forth, but a providers time is split in so many directions.... Once you meet her in person, you WILL get her undivided attention.