Forrester Research just issued a report finding that only 3% of online households in the United States have bought music from iTunes in the past year.

The 3% of online households that have purchased music from iTunes spent an average total of $35 for the year, and half of them spent only $3 or less at a time.

Dating back to the launch of the iTunes music service, the average iPod owner buys only about 20 songs. "Even at 99 cents, most consumers still aren't sold on the value of digital music," writes analyst Josh Bernoff.

The fact that iPod owners do not buy digital music is the industry's dirty little secret, and one that will likely come to a reckoning in the next year. To put these figures into comparison, only 3% of U.S. mobile phone owners report using music-enabled phones to listen to music, according to data from the NPD Group.

In other words, downloading music from iTunes is about as popular as using a phone as an MP3 player -- and that is not meant to be a positive statistic for the phone industry.

It is data like this that has driven Universal Music Group to seek an estimated $1 royalty fee for every Zune device sold by Microsoft. CEO Doug Morris has suggested he'll seek a similar rate from the iPod when it comes time to renegotiate UMG's iTunes licensing agreement this year.