Following the much anticipated IPO of Pandora last week, of course the continued success of the business now comes under additional scrutiny. Among the top metrics to monitor for ongoing growth is the number of registered users and potential advertising revenues. So far for 2011, the number of total visits to Pandora.com increased 35% for the week ending June 18th as compared to the week ending Jan 1st and new visitors represented 24% of all visits. The growth in visits has also not sacrificed the time spent on the website, the average visit time for the week ending June 18th was 12 minutes and 50 seconds, up from 11 minutes and 4 seconds from the week ending Jan 1st.

During this period of growth in visits, there has been a shift in the age groups visiting the Pandora website. The largest increase came from those between the ages of 45-54 up 19%, followed by 25-34 up 15%, when compared to the four weeks ending January 22, 2011 (this time frame was selected to line up the aggregated data based upon the 4 rolling week period with the week ending January 1, 2011).

Additionally, there was an increase in visitors with a household income between $60k and $100k and represented the largest share – just over 1/3rd of visits, for the 4 weeks ending June 18, 2011. The combined share of audience with incomes between $60k and $150k is over half of all visits to Pandora.com and offers a solid opportunity for advertisers to reach a segment with potential disposable income.

Further details about the audience for Internet Radio, from the Experian Simmons National Consumer Survey, also confirms a robust audience attractive to wide array of advertisers looking to target segments such as homeowners and households with children.