You have an e-commerce shop that you're wanting to set up a Google Ad Search Campaign for, but you still have one nagging question; which bid strategy should you use?
Before you answer this question, you want to make sure you have proper sales conversion tracking set up for your Google Ad campaign so you know which keyword and which ad is generating the best return on ad spend, not just the best cost per sale.
This is especially important if you have a lot of products that range in price.
After you have that setup, I would start any new campaign off with Manual CPC or Maximize Clicks. Once you start to receive some conversion data, roughly 20-30 conversion in 30 days, it's worth trying out Target Return On Ad Spend (tROAS) bid strategy.
You'll be able to determine if you can further optimize your campaign to maximize your return on ad spend (ROAS) while simultaneously reducing maintenance work on your campaign.
Automated bid strategies like tROAS do not always lead to better results, however. If you struggle to achieve the results you're looking for using automated bid strategies then there's nothing wrong with going back to Manual CPC or Maximize Clicks to give you more control over your campaign. This should allow you to gradually increase ROAS over time, there's just more maintenance work involved.