While I wouldn't say I really trust WAM alerts, I would rather have alerts that turned out to be not very rewarding than risk missing something mainstream that might be of interest.
Mention was made of the recent pies on American's Got Talent. Certainly the quality of the pie hits did not come anywhere close to what you get from dedicated WAM producers, but what do you expect from mainstream TV? I was still glad to see it because of the celebrities involved.