Here's what a dying tech trend looks like. Ringtones were super-hot in the middle of last decade, as everyone started to get cellphones, and have since fallen in popularity. Note the diminishing spikes around Christmas, which peaked in 2004.
One odd thing on this chart, via Google Trends: A sustained increase in interest in ringtones in the second half of this year. What could be causing this? According to mobile music Thumbplay, it might have something to do with the rise of search from smartphones, especially Android phones. But that's just a guess.