In the last few years, Google Ads, Meta (Facebook/Instagram), and TikTok have each rolled out changes that influence ad visibility, audience targeting, and key performance metrics. Below we identify recent algorithm changes on these major platforms, examine their impact on cost-per-click (CPC), engagement, and conversion rates, and provide strategies for marketers to adjust.

Google Ads: Machine Learning & Ad Performance

Google Ads has heavily embraced machine learning in its ad delivery. A notable update was the introduction of Performance Max campaigns, which let Google’s algorithm automatically allocate budget across Search, Display, YouTube, and more to maximize conversions. This automation can boost results—some advertisers report double-digit conversion lifts after switching to Performance Max—but Google’s shift to broad match and automated bidding also means advertisers have less manual control over where ads appear. Industry data indicates CPCs on Google have risen recently even as conversion rates slipped. Average search ad CPC climbed to $4.22 in 2023 (up from $4.01 in 2022) while conversion rates fell in nearly every industry—a combination that drove up cost per lead for advertisers. Google has expanded ad reach with new formats and made data-driven attribution the default to better credit conversions across touchpoints. The net effect is that Google’s algorithm changes can deliver more impressions and automate optimization, but marketers must watch for higher competition and costs.

Meta (Facebook & Instagram): From Precise Targeting to Creative Optimization

Meta’s advertising algorithms have undergone a transformation due to privacy changes and platform shifts. Apple’s iOS 14.5 update (which limited tracking) dealt a blow to Facebook’s ad targeting in 2021. Facebook’s own data showed ROAS dropping ~38% after the iOS change, and advertisers saw CPMs jump ~10% as the algorithm had less user data for optimization. Additionally, Meta removed many granular targeting categories in 2022 to improve user privacy, forcing advertisers to rely more on broader targeting. In response, Meta’s algorithm now leans on machine learning and creative content more than manual audience selection. Facebook’s advice has been to simplify campaign structure and use broad audiences (to feed more data to the AI) and to implement the Conversions API to feed back lost data for optimization. These changes mean success on Meta increasingly comes from good creative and correct conversion tracking rather than hyper-specific targeting. Encouragingly, by 2023 industry benchmarks showed Facebook ad costs stabilizing and conversion rates improving again in several sectors.

TikTok: High Engagement, New Targeting Options

TikTok’s growth has been powered by an algorithm that excels at keeping users engaged. Its feed algorithm shows content tailored to user interests, resulting in engagement rates several times higher than on Instagram. This means TikTok ads—especially those that blend in with native content—can achieve exceptional reach and interaction. TikTok is still largely a top-of-funnel channel, but the platform is adding features to improve intent-based advertising. In late 2023, it launched Search Ads, allowing advertisers to bid on keywords and show video ads in TikTok’s search results—an important shift toward capturing active intent on the app. Early results suggest this can lead to higher conversion rates from high-intent viewers. TikTok’s ad costs remain relatively efficient, but they are rising quickly (over 12% year-over-year) as more advertisers join. Also, users on TikTok often watch without clicking, so click-through rates tend to be lower than on Meta’s platforms. One study found TikTok video ads delivered 15× more impressions than Instagram Reels ads, but Reels ads had higher CTR and lower CPC. As TikTok’s ad platform matures, marketers should pair its huge reach with compelling creatives and use the new targeting tools to drive better ROI.

Strategies for Marketers

Google Ads – Let AI Work, But Set Guardrails: Embrace Google’s automation (Smart Bidding, Performance Max) to let machine learning improve results, but set guardrails. Use negative keywords and placement exclusions to avoid wasted spend, and monitor CPCs and conversions closely. Run periodic experiments (manual control vs. automated) to ensure the algorithm is meeting your goals.

Meta – Focus on Creative and Signal Quality: With Meta’s algorithm doing more optimization internally, feed it the best data and creatives you can. Send back as much conversion data as possible (via the Conversions API) to help Facebook’s AI. Simplify your campaign structure and use broader targeting so the algorithm has more data to learn from. Most importantly, invest in quality creatives (videos, Reels, etc.) that grab attention—if an ad drives strong engagement, the algorithm will deliver it to more relevant users, improving results.

TikTok – Integrate into Trends and Test New Features: Success on TikTok comes from adapting to its unique content style. Create ads that mimic organic TikToks—use popular music, effects, and a quick, storytelling approach to hook viewers. High engagement signals TikTok’s algorithm to show your ads more. Also, leverage TikTok’s new offerings: Spark Ads (to boost organic posts) and Search Ads (to capture keyword searches). If your TikTok videos get many views but few clicks, consider retargeting those viewers on other channels to capitalize on the awareness.

In summary, recent algorithm changes have reshaped how Google, Meta, and TikTok serve ads. Google’s AI-centric approach can expand reach but may raise costs; Meta’s loss of targeting data has shifted the emphasis to creative and broad learning; and TikTok’s engagement machine offers huge awareness potential and is now moving into direct response. Marketers should respond by aligning with these changes: embrace automation but monitor results, prioritize creative quality and first-party data, and leverage each platform’s strengths. By staying agile and data-driven, advertisers can continue to drive strong performance outcomes even as algorithms evolve.

References

• Starzyński, T. (2023, October 10). The biggest news from Google Ads and Facebook Ads in 2023. A summary of the announced changes! Up&More Blog.

• Goodwin, D. (2023, May 15). Search ad conversion rates down, cost per lead up in 2023. Search Engine Land.

• Holiday, T. (2022, December 27). Facebook Ads, iOS 14 changes & ecommerce data: How Apple’s ATT & IDFA update affects advertising. Common Thread Collective.

• Emplifi (2024, September 13). TikTok delivers 15X more impressions than Facebook and Instagram Reels. MartechCube.

• Stringo Media. (2023). TikTok launches search ad campaigns: A game changer for performance marketers in 2024.

• Gupta Media. (2025, February 11). The performance marketing guide to TikTok ads cost (2025).

• Bloom Digital. (2024). TikTok vs Facebook Ads: Which wins in 2024?

• MyCodelessWebsite. (2023). Performance Max statistics 2025 – 19 mind-blowing statistics.