Getting Entries that were updated after a certain day?
Your criteria for the date updated was written in the wrong syntax. It should be:

$criteria-&gt;dateUpdated = '&gt; 2015-09-02';

You can also simplify the way you query your Element Criteria Model like so:

$criteria = craft()-&gt;elements-&gt;getCriteria(ElementType::Entry);
$criteria-&gt;section = 'affiliates';
$criteria-&gt;dateUpdated = '&gt; 2015-09-02';
$affiliates = $criteria-&gt;find();


Take a look at the Working with Elements documentation for more info.