Question about books (family)

[iceminers26]

I wanted to sign up for a Sportsbet account because I wanted to purchase a FP from the point store (way cheaper than 5Dimes) and double checked with live chat before doing so to make sure I didn't already have an account there; didn't want to make multiple accounts. The CS rep tells me there is no account associated with my name or email but then asks if I have a 5Dimes account, which I do. He tells me since I already have a 5dimes account that I cannot sign up at Sportsbet.

My question, why does a family of books not want you to sign up at the various books within their family?

Thanks

ICE

[iceminers26]

Well I realized why this family of books doesn't want you to open an account at each book, the account number works at all the books within the family so my 5dimes account number allowed me to log into Sportsbet.

New question now which live chat couldn't give me an answer to save their lives, wonder if I could just purchase the Sportsbet FP and give my 5dimes info and log in to SB with that number, which I just did.