Snarf Zagyg
Notorious Liquefactionist
That is... incorrect. CBS noted that it got the highest test ratings of any drama in 15 years. CSI had been on Thursday nights for a decade, and they moved it out of the way for PoI when they saw how well it was Testing. It became the fastest growing drama between its first and second seasons, and its second season reached the #5 spot on TV at the time. It won a couple People's Choice awards as well.
The show was finally cancelled, not for bad ratings, but because it was owned by Warner Brothers, but made by CBS. Which meant that while it performed well, CBS was getting a smaller cut of the pie than they wanted. They at least had the good graces to inform the writing staff of the shortened final season, so they could wrap up the plot.
You misunderstood what I was saying.
CBS is hardly the home of cutting-edge television. The idea that there was a Nolan (other one!) penned show about AI that was airing on CBS was missed by many people in the "nerd/geek" target demo. As you acknowledge, you didn't watch it when it aired. Neither did I (I watched it after it finished, when I saw an article that basically said, "If you love great TV, you have to watch this program that you missed.")
That it did OK in CSI's time slot and following the biggest show on TV- Big Bang Theory (not better, not the same ... okay), and, more importantly, placed last in the target demographic of 18-49, indicates that it maintained its appeal with CBS's traditional, procedural viewers, but didn't manage to "sell itself" to the more desirable demo for the Tiffany network.
As it continued to de-emphasize the procedural nature of the show in order to emphasize "the good stuff," the ratings declined given that it became less similar to the other CBS shows (Criminal Minds, Blue Bloods, Elementary, The Mentalist) that did not require the earlier buy-in, culminating in the the disastrous ratings decline of season 4 and 5.