Short version: Microsoft Ads, still called Bing Ads by almost everyone, is the channel most ecommerce brands either ignore entirely or run badly on autopilot. It carries a fraction of Google's volume, which is exactly why it is profitable: far fewer advertisers compete there, clicks routinely cost less than Google's for the same searches, and the audience skews older and higher income, which lifts average order values in many categories. The mistake that ruins it is the one Microsoft actively encourages, importing your Google campaigns unchanged and never touching them again. Treated as its own channel with its own budget, negatives, and bids, Microsoft Ads is usually the highest-ROAS line in an ecommerce account, and it is nearly always the fastest win available to a brand that has never run it.
The honest framing matters here. Microsoft Ads will not replace Google. For most stores it delivers somewhere in the region of a tenth to a fifth of Google's revenue, and no amount of optimization changes the fact that fewer people search there. What it does deliver is disproportionately efficient revenue, from an audience Google is not showing you, at click prices that make the maths comfortable. Ignoring it because it is small is like refusing to pick up money because it is not a lot of money.
Why Microsoft Ads works for ecommerce
Less competition, cheaper clicks
The auction is thinner. Many advertisers, including large ones, never bother setting Microsoft up, so the same commercial search that costs a fortune on Google frequently clears at a noticeably lower price on Microsoft. Lower cost per click against a comparable conversion rate is simply better ROAS, and that gap is the entire commercial case for the channel.
A genuinely different audience
Microsoft's search audience skews older and more affluent, partly because Bing is the default on Windows devices and Edge, and because a large share of searches happen on work machines in corporate environments where the default was never changed. For categories where age and income correlate with spending, home goods, appliances, furniture, tools, high-ticket hobbies, business supplies, that skew shows up directly in average order value.
The syndicated network
Beyond Bing itself, Microsoft serves search ads across Yahoo, DuckDuckGo, AOL, and a network of partner sites. This is where the channel gets interesting and also where it needs supervision, because partner traffic quality varies and the same tools that let you monitor it also let you exclude what is not working.
Microsoft Shopping
Shopping campaigns work much as they do on Google, driven by a product feed in Microsoft Merchant Center. The feed can be imported from your Google Merchant Center account, which removes most of the setup burden, and because far fewer stores bother, Shopping impression share is often easier to win than on Google.
The import trap, and how to avoid it
Microsoft makes it trivially easy to import your entire Google Ads account, and this single feature is responsible for most of the disappointing Microsoft accounts in existence. The import is a legitimate starting point and a terrible finishing point.
Three things go wrong when brands import and walk away. First, budgets copy across at Google levels that Microsoft's lower volume cannot spend, so the account looks starved of results while actually being starved of traffic. Second, bids and target ROAS settings carry over from a more expensive auction, leaving you overbidding in a cheaper one. Third, and most damaging, campaigns never get their own negatives, their own search term reviews, or their own structure, so the channel is judged on performance nobody has ever tried to influence.
The correct pattern is import once, then immediately treat the result as a first draft: reset budgets to what Microsoft can realistically spend, loosen or reset bid targets so campaigns can actually gather data, and schedule the same weekly search term work you do on Google. From that point the account diverges from its Google parent, which is the entire point.
What a Microsoft Ads agency should actually be doing
Ongoing Microsoft management is not a lighter version of Google management, it is the same discipline applied to a channel with different economics. Specifically:
Separate search term reviews. Microsoft's syndicated network surfaces query patterns Google never shows you, some excellent, some junk. Without its own negative list the account inherits Google's blind spots and adds new ones.
Its own budget logic. Microsoft budgets should be set by what the channel can profitably absorb, not as a percentage of the Google budget. Many accounts are capped far below what they could spend at target ROAS, which is the quietest way to lose money in paid search.
Feed and Merchant Center hygiene. Microsoft Merchant Center has its own disapprovals and its own quirks, and a feed that passes Google can still be partially rejected here. Unmonitored, bestsellers silently drop out of Shopping.
Audience and device adjustments. The demographic skew is real, and the bid adjustments that follow from it are different from Google's. Desktop typically carries more weight here than in a Google account.
Honest reporting on its own terms. Microsoft should be judged on its own ROAS and its own contribution, not held to Google's volume. An agency that reports Microsoft as a footnote is usually not managing it.