His father owned a camera shop and continued with it until film became extinct and he failed to adapt to selling digital, as a result they went bankrupt. Since then, Logan has vowed to accept change as inevitable so it doesn't crush him and just keeps moving forward. He has a genius-level IQ but dropped out of college as he had other aspirations. He and Justin had been friends for over 10 years since their time at CalTech. When they started friendczar.com Justin took over the business side of things while Logan became the face of the company.
Reese met him under the alias John Wiley as a hedge fund manager and piqued his interest. Reese finds it extremely difficult to keep up with Logan as he is extremely wealthy with unlimited resources and always breaking rules to get his way. Reese finally confronts him in his office and tells him that his life is in danger and he can only protect him if Logan lets him stick with him for the next 48 hours. Logan agrees.
Logan was looking to drop his lawyer Jeremy Campbell. So Jeremy spiked his drink with Naproxen, which Logan was allergic to, to try and kill him. However, Reese was able to save his life. Logan however followed Reese and found out that he was meeting with Finch, who had earlier met Logan posing as a dry cleaner. He figures out that Finch is the brain and bank of the operation and that Reese is former special ops or ex-CIA. He also finds out that Reese and Finch don't officially exist. He is impressed that they have managed to maintain their anonymity and wonders why they do what they do.
With the help of Carter and Finch Reese exposes Jeremy as the culprit but leaves disgusted when he realizes that Logan doesn't care about his security.
Despite Reese's recommendation to lay low for a while, Logan's number comes up again while hiding in St. Petersburg, Russia. It turns out that Pierce's best friend Justin Ogilvy decided to kill him when he found out that Logan was going to go into business with Emily Morton, whose social networking program would have cannibalized friendczar.com. Reese was able to intervene again and save Logan's life while Justin was arrested.
Logan was removed as the CEO of friendczar.com following his erratic behavior and publicly telling people to hold off on buying friendczar's overvalued stock. But following his philosophy of not letting change affect him and moving forward, Logan decides to go into business with Emily. He meets with Reese who deduces that Logan already knew about Justin but didn't warn Reese as he wanted see how he works. Logan says that he figured out that Reese does what he does out of altruism. Before leaving he gives Reese a present: an expensive watch like the one Logan wears which is accurate to a nanosecond. But later Finch smashes the watch on the ground, revealing a GPS inside, and tells Reese that Logan is just curious enough to be dangerous. Reese muses on the risk posed by an eccentric billionaire with bottomless pockets and a need to know things.
When he and Reese see each other again over three years later, he helps get Reese into a fundraiser in order to help protect their current number, the President. Little did Reese know that Pierce and two other previous irrelevant numbers were sent by the Machine to create an exit strategy for Reese, Shaw and Fusco after saving their POI attracted unwanted law-enforcement attention. He told Reese that he is "working for a new cause", when in fact, he meant acting as an asset for the Machine in a similar team to Reese's own with Harper Rose and Joey Durban. (“Synecdoche”)
- After Finch removed the GPS tracker from the watch, the Machine resumes monitoring Logan Pierce and categorizes him as "Threat to Admin".
- The gift watch he gives Reese is seen again in "All In" when Finch gives it to the new person of interest.
- He is now an asset for the Machine.
- He is one of five people whose number has come up more than once since the show began, the other three being Leon Tao, Carl Elias, Joss Carter, and John Reese. However, Pierce's number came up twice in one episode, while Leon's, Elias', Carter's, and John's have come up across multiple episodes.
- He, along with Harper Rose and Joey Durban, assisted Reese, Shaw, and Fusco on their POI, creating an exit strategy for them from the Secret Service, after helping to thwart an attempted assassination of the President. All of whom are now designated as Assets by the Machine, and currently work for it in their own ways; she even sends them numbers. (“Synecdoche”)