title: Help with php/mysql mailer
body: <p>I'm working on a real estate site and need to make notification mailer: when new property is inserted on a site, people who subscribed for notification in that particular country and/or area and/or city and/or particular property operation (rental, selling) will receive a notification on email. One person could subscribe for different areas, cities, etc, not only one. One person will receive only one notification a week let say if there are new properties for him, though. And I'm thinking on how better to create a mysql table for subscribers in order to easy retrieve them. Table like:</p>
  
  <pre><code>create table subscribers(
  user_email varchar(255),
  area_id int(4));
  </code></pre>
  
  <p>is a bad idea, because if there will be let say 100,000 (looking to the future) subscribers and each will subscribe for 10 areas there will be 1,000,000 rows in a table. So, I'm looking for efficient solution to do such task.</p>
  
  <p>If you have additional recommendations, I will like to hear them.</p>
  
  <p>Thanks in advance!</p>