It doesn't hit all at once, it accrues gradually, starting 24 hours after recruiting begins (I think it's in the knowledge base somewhere) and adding each cycle little by little. So the effect of seeing it go into effect on WOTS is simply that that was the cycle where, for that player with the effort you had put in already, it tipped the scale to cross the threshold from one level of message to another.
That said, the effect really isn't that much at all. Certainly not enough to stop a poaching attempt. I would say the cosmetic benefits of simply having your name alone on a recruit assist more with keeping others from coming in than any additional spending that might be required to overcome consideration credit.