It's not at all odd thorns, just a good marketing move.
First they already have your account so you don't have to go through the 100 points rigmarole.

You may think that a serious punter would have several accounts already, but most have just a TAB and Betfair.

Also you have to think of the convenience of using one betting site, how many times did you miss out while checking prices on three or four different screens?

I haven't used betfew for at least the last six months because I couldn't get matched for the amount I wanted but with this, I might give it a try.

Cheers