To be fair, she was friends with Francine for years, and she DID use the gospel choir.
To some extent people like Lauren Pope and Rylan wanted to hang out with her, not the other way around. She's seen as a bit of legend to these type of people.
I don't dispute shes good at using the world of showbiz to keep her profile up,its probably quite smart - but in anyway, famous people do tend to hang out with each other, attend the same functions, so is it that unusual?
Majority of people in the public eye have their own circle of friends that are not in the business. Normally they associate with others in the buisness only for special events, eg: award shows, charity events, business (film, TV premiers) etc. if lucky they will find a few true close friends in the same business.
Katie and her friends do ride on others coat tails a lot and I agree this is business savvy, It keeps them relevant and in the public eye. It's the name of the game for UK z listers.