Update Oct. 1: Google has updated the sunset dates and error codes.

Google Ads announced a coming change to ad delivery options that will start September 17. The accelerated delivery option will be removed and standard delivery will be the only option for Search and Shopping campaigns, as well as for campaigns with shared budgets.

Automatic switch by October 1. Any Search or Shopping campaigns and shared budgets using accelerated delivery will be switched over to standard delivery automatically by October 1.

The accelerated delivery option will still be available for Display and Video campaigns, Google said.

Why the change? Advertisers typically opt for accelerated delivery when the goal is to drive as many conversions as possible within a target cost per conversion. This is particularly common for e-commerce advertisers that are willing to spend as much as possible as long as their margins make sense. They choose the accelerated delivery option and set their daily budgets high enough to ensure their ads are served as often as possible throughout the entire day. It’s been a particularly popular option for Shopping campaigns.

However, Google says, the way that accelerated delivery works can make it an inefficient option. (And have said as recently as last month not to use it.) Obviously, if you do have a capped daily budget, choosing the accelerated option can mean your ads stop serving well before the day ends. But Google also notes, “this method can increase CPCs due to increased competition early in the day, or unintentionally spend most of your budget in earlier time zones.”

Google says standard delivery has been improved to be more predictive: “Standard delivery takes into account expected ad performance throughout the day and is better at maximizing performance within your daily budget.”

With standard ad delivery, your budget is paced throughout the day or the periods of time you’ve scheduled your ads to run. Google says it “optimizes your spend to be more reflective of targeted inventory user search (eg.user searches for your product/service),” as opposed to accelerated delivery, which Google says is “less optimized.”

Your options. Google recommends choosing the maximize conversions or maximize clicks bidding strategies to indicate your performance priority for campaigns that had been using accelerated delivery. And, of course, use ad scheduling to manage when your ads are shown and bid adjustments to increase and decrease bids during certain times of day . (Though Google’s ad scheduling only takes your account’s time zone into account.)

Why we should care. Yes, this is a loss of yet another lever and will likely be decried by many advertisers. But it’s also another indication that Google believes its machine learning algorithms are now better equipped to optimize campaigns. In this case, it’s saying it can better optimize ad delivery based on the advertiser’s goals and query contextual signals than the relatively blunt option of showing ads as often and early as possible. Time will tell for those currently using accelerated delivery. Start preparing for this change now.