What is Paid Search?
Also known as: Search advertising, PPC, SEM
What is paid search?
Paid search is buying ad placements on search engine results pages. An advertiser picks keywords, writes ad copy, sets a bid, and pays each time a user clicks. Google Ads owns roughly 84% of the global search ad market, per Statista's 2024 report. Microsoft Advertising covers most of the rest.
The model is simple. The engine matches a user's query to advertisers bidding on related keywords. An auction runs in milliseconds. The winning ads load above the organic results, marked "Sponsored."
Paid search is the fastest channel in performance marketing. A campaign launched at 9 AM can drive a sale by 9:15.
How paid search auctions work
Every Google and Bing search triggers a second-price auction. The advertiser with the highest Ad Rank wins the top slot, but pays only one cent more than the next-highest Ad Rank requires. Per Google Ads documentation, Ad Rank combines bid, Quality Score, ad format impact, and the user's context.
Three inputs decide the winner:
- Bid. The maximum CPC the advertiser is willing to pay.
- Quality Score. A 1 to 10 rating of expected CTR, ad relevance, and landing page experience.
- Ad assets and format. Sitelinks, callouts, and structured snippets boost expected impact.
The actual cost per click is rarely the full bid. The formula runs roughly:
Actual CPC = (Ad Rank of competitor below / your Quality Score) + $0.01A high Quality Score lets a smaller bidder beat a larger one. That dynamic is why ad copy and landing page work matter as much as budget.
Microsoft Advertising uses the same second-price model, per Microsoft Ads documentation. Bid strategies and match types translate directly.
Paid search ad formats
Search ads come in four main formats. Each format serves a different commercial intent.
| Format | Where it shows | Best for | Visual |
|---|---|---|---|
| Search Ads | Top and bottom of SERP | Lead gen, B2B, services | Text only, headlines and description |
| Shopping Ads | SERP carousel and Shopping tab | Ecommerce | Product image, price, merchant |
| Local Service Ads | Top of local SERP | Plumbers, lawyers, contractors | Photo, reviews, "Google Screened" badge |
| Performance Max | All Google surfaces (Search, YouTube, Display, Gmail, Maps) | Multi-channel ecommerce and lead gen | Mixed assets, AI-driven placement |
Search Ads remain the workhorse. Shopping dominates ecommerce results and now drives the majority of retail ad clicks on Google, per Search Engine Land. Performance Max is the newest format and bundles every Google surface into one campaign type.
Quality Score and Ad Rank explained
Quality Score is Google's 1 to 10 rating of how relevant an ad is to a user's search. Per Google Ads documentation, it blends three components: expected CTR, ad relevance, and landing page experience. A score of 7 or higher counts as healthy.
Ad Rank turns Quality Score into auction position. The formula:
Ad Rank = Bid x Quality Score + Expected impact from ad assetsTwo practical effects follow from this. First, bidding higher does not guarantee position one. A keyword with a Quality Score of 4 can lose to a competitor at half the bid with a Quality Score of 9. Second, the cheapest path to the top of the page is improving relevance, not raising bids.
The biggest Quality Score lever is ad-copy-to-keyword alignment. Headlines that mirror the searcher's exact phrasing pull CTR up fast. Landing page experience runs a close second. Slow pages and weak content tank the score regardless of bid.
Paid search vs SEO
Paid search and SEO both target the same SERP. The mechanics, costs, and timelines differ sharply.
| Dimension | Paid search | SEO |
|---|---|---|
| Time to first click | Hours | 6 to 12 months |
| Cost per click | $1 to $50+ | Effectively zero after publish |
| Position control | Bid more, rank higher | Earned through relevance and links |
| Stops when budget stops | Yes | No, organic rankings persist |
| Best for | Intent-rich, time-sensitive, transactional terms | Long-tail, informational, brand-building |
| Measurement | Click-level attribution in real time | Slower signals via Search Console |
The two channels work better together than apart. Paid search captures the buyers ready today. SEO compounds traffic for the queries with lower commercial intent but high volume. Bidding on a term while ranking for it organically lifts total clicks roughly 50 percent more than either channel alone, per a Google research study.
Real-world example with numbers
A B2B SaaS company sells inventory management software. The team launches paid search on three keyword clusters.
- Cluster A: "inventory management software." Volume 18,000 per month. Avg CPC $14.20. KD 84.
- Cluster B: "inventory software for ecommerce." Volume 1,900 per month. Avg CPC $7.40. KD 42.
- Cluster C: "shopify inventory app." Volume 720 per month. Avg CPC $4.10. KD 28.
Month one budget: $12,000. Cluster A burns 60 percent of spend at a 1.1 percent conversion rate. Clusters B and C convert at 4.8 and 6.2 percent.
The team reallocates. They move 80 percent of budget to Clusters B and C. They tighten ad copy to mirror the long-tail phrasing. They build a separate landing page per cluster, which lifts Quality Score from 5 to 8 across the board.
Month three results. Total spend stays flat at $12,000. Conversions climb from 41 to 137. Cost per acquisition drops from $293 to $88. Same product. Same channel. Different keyword strategy and Quality Score.
Paid search in 2026 (AI Overviews, Demand Gen)
Paid search adapted to the AI Overview era. Google now serves AI-generated answers above the organic results on roughly 47 percent of informational queries, per Search Engine Land's 2025 SERP study. Commercial queries still show traditional ads in the top slot.
Three shifts changed how performance teams operate this year:
- AI Overviews compress organic. Informational SEO traffic dropped 18 to 34 percent on terms where AI answers fully resolve the query. Paid search ads moved further up the page.
- Demand Gen replaced Discovery campaigns. Google's Demand Gen format blends YouTube, Discover, and Gmail placements. The format runs on the same auction logic as Performance Max but with creative-led bidding.
- Match types loosened further. Broad match plus Smart Bidding became Google's recommended default. Negative keyword lists matter more than ever. A poorly maintained negative list bleeds 15 to 25 percent of budget on irrelevant queries.
Paid search is not shrinking. It is moving up the funnel, into more surfaces, and further into AI-driven bidding. Strong keyword research, tight ad copy, and disciplined Quality Score work still beat the algorithm. The unit economics of search advertising hold.
Related terms
Frequently asked questions
What is the difference between paid search and PPC?
PPC is the pricing model. Paid search is the channel. Almost all paid search ads are billed PPC, so the terms get used interchangeably. PPC also covers display, social, and shopping ads. Paid search is specifically ads on Google, Bing, and other search engine results pages.
How much does paid search cost?
Average CPC across Google Ads sits around $4.66 across industries, per WordStream's 2024 benchmark report. Legal and insurance keywords run $50 or more per click. Ecommerce averages $1 to $2. Total monthly spend is bid times click volume, capped by the daily budget.
Is paid search better than SEO?
Neither replaces the other. Paid search delivers traffic the day a campaign launches. SEO compounds for years but takes 6 to 12 months to rank. The top performers run both. Paid search captures intent-rich queries today. SEO owns the long tail forever.
What is a good Quality Score?
Seven or higher is good. Ten is the ceiling. Per Google Ads documentation, Quality Score blends expected click-through rate, ad relevance, and landing page experience. A score of 8 can outrank a competitor bidding 30 percent more at a score of 5.
Do AI Overviews kill paid search?
Not yet. Google still serves text ads above and below AI Overviews on commercial queries. Click volume on transactional terms held steady through 2025, per Search Engine Land. Informational queries lost the most organic traffic. Paid search formats moved up the page, not off it.