SEO vs PPC: paid search engine marketing compared with organic search

PPC (pay-per-click) is paid search engine marketing: you bid on searches in Google Ads or Microsoft Advertising, your ad appears in the sponsored slots, and you pay when someone clicks. SEO (search engine optimization) works on the unpaid organic results around the ads, where you can't buy a position at any price.

Many businesses that depend on search use both. This page explains how each decides who's shown and what you pay, what "PPC in SEO" means in practice, what changes in AI Overviews, and what to ask when you compare SEO and PPC services.

How PPC works in Google Ads

Cost-per-click bidding means you pay for each click on your ads. You set a maximum CPC, the highest amount you're willing to pay for a click; the amount you're actually charged is your actual CPC, and Google says it's often less than the maximum.

Which ads show, and in what order, is decided by Ad Rank, which Google calculates every time someone searches. It's based on six factors: your bid, the quality of your ads and landing page, the Ad Rank thresholds, the competitiveness of the auction, the context of the search (terms, location, device, time) and the expected impact of ad assets. Google adds that higher-quality ads can often lead to lower CPCs.

Quality Score, the 1-to-10 rating you see per keyword, is easy to mistake for the thing that sets your price. Google calls it a diagnostic tool, built from expected clickthrough rate, ad relevance and landing page experience, and says plainly that Quality Score is not an input in the ad auction.

How organic rankings work

Organic results go through three stages: Google crawls pages, indexes them, and serves the ones it judges most relevant to each search. There's no bid and no fee for position, so the page itself has to be the best answer, and it has to be crawlable and indexable before it can compete at all. The on-page SEO checklist covers what that takes on each page.

SEO vs PPC side by side

Compared on the points that decide a budget:

PPC in SEO: using ad data to plan organic work

"PPC in SEO" usually means using what paid search teaches you to decide where organic effort goes. Ads answer quickly the questions that SEO takes much longer to reveal:

• The search terms report shows the real searches that triggered your ads and how they performed. Searches that convert are candidates for a dedicated page; irrelevant ones become negative keywords.
• The paid and organic report, available once Search Console is linked to Google Ads, lets you find queries where your site appears in organic results with no ad, and queries where you have ads but little organic presence.
• Ad text tests show which promises earn clicks. The winners are good raw material for title tags and meta descriptions. Google may not use them as written, since title links draw on the title element, headings and other text, and snippets come mainly from page content.
• Landing page tests show which layout turns visits into enquiries. The same page usually serves both channels, so the lesson carries over to organic visitors.

When to use PPC, SEO or both

• PPC first: a new site, a launch, a seasonal offer, or a valuable search you can't rank for yet.
• SEO first: questions people ask before they buy, evergreen products and services, and searches where clicks are expensive.
• Both: your most valuable commercial searches. Ads cover the gap while pages earn rankings, and the paid and organic report shows when the overlap is worth paying for.

Neither channel buys the other. A PPC budget doesn't lift organic rankings, because Google doesn't accept payment for them, and an organic number one doesn't reserve the ad slots above it. Budget for each on its own merits.

PPC and SEO in AI Overviews and AI Mode

Google now sells ad space inside its AI search features. Ads can appear above or below an AI Overview in every country where AI Overviews are available, and within AI Overviews and AI Mode in a list of English-language markets that includes the US, India, Canada and Australia. Search, Shopping and Performance Max campaigns are eligible automatically. You can't target these placements on their own or opt out of them separately from Search, and their results are reported in aggregate within your normal campaign reports, with the triggering queries in the search terms report.

The organic side needs nothing extra beyond normal SEO: indexed pages that can show a snippet are eligible as supporting links. How AI search fits a wider plan is in SEO marketing and AI search.

SEO and PPC services: what to ask

SEO and PPC management are different jobs even when one agency sells both. Paid search management is daily work on bids, budgets, negative keywords and ad tests. SEO is slower: audits, page improvements, content and earning links. When you compare SEO and PPC agencies, ask:

• Is the management fee separate from ad spend, and is it flat or a percentage of spend?
• Will the Google Ads account and Search Console property be in your name, so the history stays with you?
• How are conversions tracked, and will paid and organic be reported separately?
• What will the SEO work actually include each month, beyond the report?

If a proposal calls all of this "SEM", the two meanings of SEM will help you read it. We don't manage PPC campaigns. For the organic half, our done-for-you service audits the pages that matter most and fixes them.