diff --git a/README.md b/README.md
index e9b50e9..aee6bf1 100644
--- a/README.md
+++ b/README.md
@@ -18,6 +18,8 @@ Sample success:
 {"success":true}
 ```
 
+Note that success means that the message was sent to Textbelt's list of providers.  We can't guarantee delivery on your network.
+
 Sample failure:
 
 ```
@@ -74,6 +76,8 @@ Canadian and international support may not be complete.  Refer to the list of su
 
 ### Notes and Limitations
 
+ * Some carriers are picky about which messages they deliver. A "success" response from Textbelt means that your message was given to the carrier.
+
  *  IP addresses are limited to 75 texts per day.  Phone numbers are limited to 3 texts every 3 minutes.  If you need increased limits, please contact admin@textbelt.com.
 
  *  Some carriers may deliver text messages from "txt@textbelt.com"
diff --git a/server/views/index.html b/server/views/index.html
index 9c6b99a..ad5b970 100644
--- a/server/views/index.html
+++ b/server/views/index.html
@@ -53,6 +53,8 @@ body {
 <pre><code>{"success":true}
 </code></pre>
 
+<p>Note that success means that the message was sent to Textbelt's list of providers.  We can't guarantee delivery on your network.</p>
+
 <p>Sample failure:</p>
 
 <pre><code>{"success":false,"message":"Exceeded quota for this phone number."}
@@ -79,6 +81,7 @@ Canadian and international support may not be complete.  Please refer to the lis
 <h3>Notes and Limitations</h3>
 
 <ul>
+<li><p>Some carriers are picky about which messages they deliver. A "success" response from Textbelt means that your message was given to the carrier.</p></li>
 <li><p>IP addresses are limited to 75 texts per day.  Phone numbers are limited to 3 texts every 3 minutes.  To report abuse or request increased limits, please contact ianw_textbelt at ianww.com.</p></li>
 <li><p>Some carriers may deliver text messages from "txt@textbelt.com"</p></li>
 <li><p>Supported U.S. carriers: <span class="mute">Alltel, Ameritech, AT&T Wireless, Boost, CellularOne, Cingular, Edge Wireless, Sprint PCS, Telus Mobility, T-Mobile, Metro PCS, Nextel, O2, Orange, Qwest, Rogers Wireless, US Cellular, Verizon, Virgin Mobile.</span></p></li>