Applies a tag after any 5 pages on the site are viewed

wpf-apply-tags-after-x-pageviews.php

<?php

/**
 * Track total page views across the site and apply a tag with WP Fusion if the view count exceeds 5.
 */

function wpf_track_total_page_views() {

	// Replace with the WP Fusion tag name you want to apply
	$wp_fusion_tag = 'Example Tag Name';

	$target_view_count = 5;

	//
	// Don't edit after here:
	//

	$wp_fusion_tag = wpf_get_tag_id( $wp_fusion_tag );

	// Ensure user is logged in
	if ( ! is_user_logged_in() ) {
		return;
	}

	$user_id     = get_current_user_id();
	$meta_key    = 'total_page_view_count';
	$page_views  = (int) get_user_meta( $user_id, $meta_key, true );

	// Increment total page view count
	++$page_views;
	update_user_meta( $user_id, $meta_key, $page_views );

	// Apply WP Fusion tag if view count exceeds the target and tag hasn't been applied yet
	if ( $page_views > $target_view_count ) {
		wp_fusion()->user->apply_tags( array( $wp_fusion_tag ), $user_id );
	}
}

add_action( 'wp', 'wpf_track_total_page_views' );