I'd like to make a stronger case for including tags for each answer. Anybody attempting to do user analytics (as you've correctly divined) then has to perform N vectorized calls to /questions/ids, which is bounded by URL length, not number of IDs—an incredibly brittle solution that wastes a ton of API calls and bandwidth just to get a short list of tags. IOW, providing tags (even as an optional return) is a valuable bit of information about an answer, and punches above its weight in terms of bandwidth & API request savings. Please reconsider and add this feature!