diff --git a/README.md b/README.md
index ff259f6..4c2e9ec 100644
--- a/README.md
+++ b/README.md
@@ -229,7 +229,9 @@ The legacy `402` with `code: "AUTH010"` means the domain isn't enabled. `extract
 
 #### Preparing a domain
 
-`client.prepare_domain(domain, example_urls)` submits a domain for Extract (`POST /v1/extract/prepared-domains`), and `client.prepared_domain_status(domain)` reads where it is (`GET /v1/extract/prepared-domains/{domain}`). Both return the parsed status object. Pass the domain without a scheme and 1 to 5 example URLs, one per kind of page you want to extract. These calls cost no credits.
+`client.prepare_domain(domain, example_urls)` submits a domain for Extract (`POST /v1/extract/prepared-domains`), and `client.prepared_domain_status(domain)` reads where it is (`GET /v1/extract/prepared-domains/{domain}`). Both return the parsed status object. Pass the domain without a scheme and 1 to 5 example URLs on it. These calls cost no credits.
+
+One example URL works; we recommend 3 or more of the same page type (e.g. 3 product pages), because Extract compares pages of one type to check the fields it found and fill in fields one page is missing. Several page types can share the 5 (e.g. 3 product pages + 2 search-result pages).
 
 Preparation takes minutes, and the client does not wait for it. Poll the status until it is no longer `"preparing"`:
 
@@ -243,7 +245,12 @@ client = ZenRowsClient("YOUR-API-KEY")
 try:
     status = client.prepare_domain(
         "www.scrapingcourse.com",
-        ["https://www.scrapingcourse.com/ecommerce/"],
+        [
+            # Three pages of one page type: product pages on the same domain.
+            "https://www.scrapingcourse.com/ecommerce/product/abominable-hoodie/",
+            "https://www.scrapingcourse.com/ecommerce/product/adrienne-trek-jacket/",
+            "https://www.scrapingcourse.com/ecommerce/product/aeon-capri/",
+        ],
     )
 except PreparedDomainError as err:
     # e.g. 409 in_progress, 429 out_of_allowance, 503 overloaded
diff --git a/src/zenrows/client.py b/src/zenrows/client.py
index bae8a5e..61df0c7 100644
--- a/src/zenrows/client.py
+++ b/src/zenrows/client.py
@@ -325,7 +325,11 @@ def prepare_domain(self, domain: str, example_urls: list[str]) -> dict:
         `ready` or `failed`), `state`, `submitted_at`, `updated_at`.
 
         `domain` is the domain without a scheme. `example_urls` are 1 to 5
-        URLs on that domain, one per kind of page you want to extract.
+        URLs on that domain. One works; we recommend 3 or more of the same
+        page type (e.g. 3 product pages), because Extract compares pages of
+        one type to check the fields it found and fill in fields one page is
+        missing. Several page types can share the 5 (e.g. 3 product pages +
+        2 search-result pages).
         Submitting a domain that is already prepared returns its current
         status instead of starting a new run.