Thumbtack automates Google RSA ad copy generation with LLMs for personalized SEM campaigns
Thumbtack's SEM ad copy was produced from a single template, leaving over 80% of assets identical across all ad groups with no keyword-level personalization—making tailored ads for hundreds of ad groups nearly impossible at scale.
How it works
Common implementation structure
How this type of workflow is generally built, generalized across documented cases — not tied to any one vendor's stack. Click any stage to read what happens there. Specific products that implement these stages appear in “Tools commonly seen” below.
Stage 1 · Ad group inputs assembled
LLM generation is initiated with the ad group name, keywords, ad copy best practices, and character limits as inputs.
Tools used
Large Language ModelsGoogle Responsive Search Ads
Outcome
The LLM approach saved several months of review time and enabled personalization at scale across all ad groups (previously impossible); the PoC produced a 20% lift in traffic and 10% lift in conversions, and phase 4 results showed statistically significant improvement in impressions, CTR, and conversions.
What failed first
The templated approach produced identical, repetitive ad copy—11 of 15 headlines were the same across all ad groups, device-specific variants were absent, and poorly performing ads were never updated due to the manual effort required.