public function increase_purchase_count( $count = 1 ) {

    // Make sure it's numeric and not negative
    if ( ! is_numeric( $count ) || $count != absint( $count ) ) {
      return false;
    }

    $new_total = (int) $this->purchase_count + (int) $count;

    do_action( 'edd_customer_pre_increase_purchase_count', $count, $this->id, $this );

    if ( $this->update( array( 'purchase_count' => $new_total ) ) ) {
      $this->purchase_count = $new_total;
    }

    do_action( 'edd_customer_post_increase_purchase_count', $this->purchase_count, $count, $this->id, $this );

    return $this->purchase_count;
  }