Larry,
To answer your question, yes it helps and every casino takes care of its VIP players well. They contribute to almost over 85% of the revenue for any casinos. Most of the service is personalised and hence not public information. The casinos try their best to retain these players for as long as possible and I have seen high rollers playing with the same casino for over 5 years.
If the casino makes money, the affiliates definitely makes more.
A point to be noted is that the casinos have to take equally good care (financial spend will differ based on the player losses) of the middle and lower rung players. This is due to 2 simple reasons –
1) The smaller players graduate into the higher category and with good service you can be guaranteed of a regular flow of these players into the VIP category
2) A few VIP players moving away to another casino or even going on an extended vacation can hit your bottom-line badly. So it is better to keep the constant flow from lower categories to the VIP category.
Simple thumb rules 
@Lyceum 199191 wrote:
I’m working with the editor of CAP magazine on an article about VIP service and how it affects affiliates’ revenue (that is, increases retention of the most lucrative customers). Operators seem to put varying degrees of emphasis on VIPs – some are very creative about it, others just offer standard benefits.
I’d be interested in your opinions and observations…
First, if one of the casinos you represent does a particularly good job of taking care of VIP players, now’s the time to brag about it.
I’d also like to hear what you think about my thesis that investing in VIP benefits pays off by retaining the best players longer.
You can reply here or send me an email: [email protected].
L
Hope this helps.