Google vs. Microsoft
The biggest difference between Google and Microsoft is reach: Google is larger than Microsoft, which includes Bing, Yahoo and AOL traffic in its network. According to Statista, that difference is around 63 percent market share for Google and 25 percent market share for Microsoft in the United States, so Google is around 2.5 times the size of Microsoft. You would think that suggests you should focus your initial efforts on Google to get in front of more users, right? Perhaps, but everyone else is also thinking that. There is less competition on Microsoft, and you might be able to acquire the same amount clicks at a lower cost per click and improve your ROI in the process.
Search vs. shopping
Search ads are the sponsored listings that appear at the top of search engine results when you enter in a keyword (mostly text links). Shopping ads are the product listings that appear in the “shopping” sections of those same search engines (mostly visual product images). The shopping ads are typically a direct feed of your products from your website created using a management tool like Feedonomics or DataFeedWatch. If you're in ecommerce, the natural instinct is to advertise in both sections. That may work fine for you, or it may not, as we learned at my business, Restaurant Furniture Plus.
Desktop vs. mobile
Over the last 20 years — thanks to the innovations of Apple, Android, Samsung and others — searches from mobile phones have surpassed searches from desktop PCs for many companies. The problem is that most businesses have optimized their user experience for desktop, not mobile, and search engine algorithms produce results differently depending on the perceived user experience and site speed of those different desktop and mobile channels.