I sell tickets on the secondary market, so I'll answer for them. They aren't doing it because it's risky and the margins are small. Probably the least risky thing they could do with ticket trading is monitoring ticket listings in real time and buying ones that are listed below the prevailing market price, for events that are expected to have an increase in prices over time. However, 85% of events decrease in price as it gets closer to the event, until the last 48 hours which are harder to predict. Of course, the most money is to be made from buying from Ticketmaster at face value before events sell out.
Also, the secondary ticket market is very sensitive to momentum, so if SeatsGeek did a lot of trading they could unintentionally move the market in ways that cancelled out their profit.
They can make more reliable money from the affiliate fees on their sites. The prices for sold out events may vary by 40%, but the sites like Stubhub and Ticket Network take another 20% which makes it very difficult to flip tickets for already sold out events.
Something that often works better is short selling tickets for events that haven't gone on sale yet -- the price will crash down to the true market value after the market has more than a few tickets available.
Also, the secondary ticket market is very sensitive to momentum, so if SeatsGeek did a lot of trading they could unintentionally move the market in ways that cancelled out their profit.
They can make more reliable money from the affiliate fees on their sites. The prices for sold out events may vary by 40%, but the sites like Stubhub and Ticket Network take another 20% which makes it very difficult to flip tickets for already sold out events.
Something that often works better is short selling tickets for events that haven't gone on sale yet -- the price will crash down to the true market value after the market has more than a few tickets available.