Final Answer:
To collect the number of comments users posted to a web page with analytics tools like Go ogle Analytics, you would use: D. Custom Metric
Step-by-step explanation:
A custom metric is a feature that allows you to measure data that is not tracked by default within the analytics platform. Here's how to use a custom metric to track the number of comments:
1. Define the Custom Metric: In your analytics tool, define a new custom metric. For example, create a metric titled "Comments Posted."
2. Implement Tracking Code: Adjust the tracking code on your website to push an event or a hit to the analytics server every time a user posts a comment. The code would increment the "Comments Posted" metric by one for each comment made.
3. Configure Reporting: Set up your analytics reports to include the "Comments Posted" metric, so you can analyze the data along with other metrics related to user engagement.
Other options mentioned don't fulfill this purpose:
A. Custom Channel Groupings - This feature is used to group traffic into customizable channel categories, which is not applicable for tracking user interactions like comments.
B. Calculated Metric - While calculated metrics can be used to perform calculations on existing metrics, they still depend on base metrics being tracked. In this case, posting a comment is not a default metric hence cannot be calculated from other metrics without first defining it.
C. Custom Dimension - Custom dimensions are used to segment and filter data based on non-numeric parameters. For example, tracking the category of a blog post or the membership level of a user, which doesn't apply to the counting of posts.
Using a custom metric is the correct approach to track the number of comments that users make on a web page.