Heavy Cyber Monday traffic crashed several retail websites including Target stores and PayPal, which experienced heavy payment processing traffic.
Target's website was back up and running by late morning, but crashed early in the day due to high traffic.
"Both traffic and order volumes are exceeding Target's Thursday Black Friday event, which was our biggest day ever for online sales. To help manage the volume, we have been metering traffic to the site. We have teams working diligently to restore Target.com to full functionality," a Target spokesperson said in a statement.
Target has had trouble in the past maintaining website functionality. Heavy traffic crashed the site following the release of its popular Lilly Pulitzer collection.
PayPal experienced problems processing payments, posting a note to its merchant notification page citing a "major impact to PayPal APIS and PayPal website."
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