A minor hint for the uninitiated:
The first episode, "Rollercoaster", garnered a total of 10.8 million viewers when aired as a preview on August 17, 2007, holding onto more than half the record-setting audience of its lead-in, High School Musical 2. When Phineas and Ferb officially debuted in February the next year, it proved cable's number one watched animated series premiere by "tweens". Throughout the first quarter that followed, it peaked as the top-rated animated series for ages 6–10 and 9–14, also becoming number three animated series for all of cable television for viewers age 6–10. By the time the commissioning of the second season was announced in May 2008, the series had become a top-rated program in the 6–11 and 9–14 age groups.
The Disney Channel's airing of "Phineas and Ferb Get Busted" was watched by 3.7 million viewers. The episodes "Perry Lays an Egg" and "Gaming the System" on Disney Channel achieved the most views by ages 6–11 and 9–14 of any channel in that night's time slot. This achievement propelled the series to the number one animated telecast that week for the target demographics. On June 7, 2009, Disney announced that the show had become the number one primetime animated television show for the demographics 6-10 and 9-14.
The premiere of "Phineas and Ferb's Christmas Vacation" garnered 2.62 million viewers during its debut on Disney XD, the most watched telecast in the channel's history (including Toon Disney) and the number three program of the night in all demographics. It received 5.2 million viewers for its debut on Disney Channel. It was the highest rated episode of the series to date and 5th highest for the week.
The premiere of "Phineas and Ferb: Summer Belongs To You!" garnered 3.862 million viewers, was watched it with 22% of kids 2–11, 13% of teens, 5% of households, and 3% of adults 18–49, also being the #1
program on that night and it was 25th for the week in viewership. On Disney XD, the episode ranked in the channel's top 3 telecasts of the year in viewers with 1.32 million, and Boys 6–11 with 365,000, with a 2.9 rating. The hour telecast on August 2, 2010 is currently the Emmy-winning animated series' No. 2 telecast of all time on Disney XD in Total Viewers, in kids 6–14 with 677,000 and a 1.9 rating, Boys 6–14 with 435,000 and a 2.3 rating, and kids 6–11 with 542,000 and a 2.2 rating, Boys 6–11 and Boys 9–14 235,000 with a 1.9 rating, behind only December 2009's "Phineas and Ferb's Christmas Vacation".Edited at 2012-02-11 12:53 am (UTC)