Amazon’s digital sales grew 29% for Q1 2012 compared to Q4 2011, while  iTunes sales only grew 2% during the same period. This is according to a new report from intelligence company eDataSource, which estimated of the sales of both iTunes and Amazon’s digital business as part of its new e-commerce monitoring service.

The report included Kindle content, MP3 sales, streaming videos and Android apps when measuring Amazon’s digital business and included music, video, apps and digital print in  iTunes sales.

While Amazon’s business appears to be growing faster in these numbers, the report points out that iTunes sales still are 3.5x higher than Amazon’s digital sales volume domestically. In addition, the report found that iTunes customers spend 61% more than Amazon digital customers.

The press release has more: “Amazon’s digital sales are heavily dominated by Kindle Edition digital print, which have accounted for 77% of $ sales over the last six months.  Video on demand accounts for 8%, music 12% and apps account for only 2% of sales.  That product mix has shifted recently however.  By March 2012 video on demand’s percentage of sales had grown by 25% to 10% of sales, for example.”