For the quarter ended Aug. 31 the Richmond, Va., company reported earnings of $1.72 a share on revenue of $7.99 billion. Analysts surveyed by FactSet were expecting the company to report earnings of $1.88 a share on revenue of $6.91 billion.
The company's omnichannel platform gives customers "the ability to progress to a sale or buy regardless of how they shop with us," Chief Executive Bill Nash said in a statement.
At last check CarMax shares were down 8.6% to $133.84.
CarMax revenue for the quarter rose 49% year over year after it sold 419,895 vehicles through its retail and wholesale channels. That sales number was up nearly 20% year over year.
The used car company bought 364,263 vehicles in the quarter, a 59% increase over a year earlier.
Gross profit per retail used unit was $2,185, which was in line with historical levels and down slightly from a year earlier.
CarMax remains "on track to bring our fully self-service online experience to all of our retail consumers by the end of the fiscal year," Nash said.