First of all this service is one that has been needed for a long time now. It would be even better if there could be an alternative server/service offered in case the IP server was down.
Secondly, to everyone who is complaining about owning a lifetime license. You have 3 options really.
Upgrade (for free) your current license to the officially recognized license which gets all of the newest features such as the Spam monitoring system, purchase a new license, or do with out it all together.
The Spam monitoring system is not required for your forum to live up to its full potential. IPS is adding on costs to their plate by offering this service & as such they deserve to be compensated by those who will use it.
My only concern is with this addition, will there be a price increase in the future for further renewals?
If there will be, then this service should be an optional service.