I find it difficult to believe that 48 people in NAC are spending exactly the same amount of cash per week on CI. we have moved up at the same rate.
It has a cap of course so you can't go and throw a million bucks at it one week and shoot up 20 points.
So all of you are technically spending more than you need to. All you're really gaining is any time lost at which point your progress would normally slow, because the most efficient thing in the world would be to only increase your marketing outlay as your progress slowed. But it would be exceedingly difficult to do accurately. By the time you noticed the slow down you will have lost some of the CI you could have if you'd just set your expense higher to begin with.
Eventually you will notice that each of you start to separate on the chart. It's not an instantaneous change when one guy hit 70 and then stops. He begins to slow as he approaches 70 but you do not because your outlay is sufficient for an 80, so you don't start to slow until you get to about 75. Others move on past you as you slow and so on and so forth.
If you don't think the progress slows, it's a very easy test -- just don't change your outlay. Eventually your progress will slow as you approach whatever CI that outlay will maintain; surely you've noticed your weekly CI gain slow as it approaches a finite point. It'll take months to earn that last few points. Then, as you notice it slow to a small 0.1 change per week add some more money to your outlay -- you'll get a huge increase your weekly CI gain. Then cancel that new program and add one that costs half as much per week, you'll note your weekly increase falls considerably.