First, it’s important to understand what the campaign objective actually does. Most advertisers confuse the objective for the primary factor that controls ad delivery. It’s not.
Just because your campaign objective is Sales doesn’t mean that delivery will be optimized for sales. Your performance goal does that.
You could pick a sales objective and set a performance goal of link clicks, landing page views, or something else. Your ads will be optimized to deliver to people most likely to perform those actions — not necessarily purchase. The objective doesn’t matter.
What the Objective Does
That doesn’t make the objective meaningless. What the objective does is streamline the campaign creation process. It removes options that you may not need and makes certain options available within the ad set.
SIDEBAR: Meta could make this less confusing by removing performance goals that are irrelevant to the objective. There’s no reason to make Link Clicks and Landing Page Views optimization available under the Sales objective. Make those only available for Traffic.
Instead, most performance goals are available for multiple Campaign Objectives. That’s just confusing.
But, I digress…
What You Should Do
Keep this simple. Start with an objective that represents what you want to accomplish. The most important step will be your conversion location and performance goal. These are selected in the ad set and should be your priority.
If the conversion location and performance goal you want aren’t available, pick a different campaign objective. Eventually, you’ll have a much better sense of what conversion locations and performance goals are available for which objectives.
For an overview, check out my guide to the 21 performance goals.