We're presently trying to come up with a way to filter out what we are calling "ghost clicks" (that is, clicks from a spam filter like Barracuda, not from a real person) from our Marketo activity log data, which we've downloaded to our data warehouse. This topic has been discussed several places, but apparently without much resolution (see here, and here, and here, for example).
I'm wondering if the timing of an activity can be used to spot "fake" clicks from a spam filter - so, if a "click email" event happens only a few seconds after the email send activity, maybe that isn't real.
But are the timestamps on Marketo's activity log really accurate down to the minute and / or second? If a "send email" activity is logged at 19:46:11.000 and a "click email" activity occurs at 19:46:53.000, is it true that the email was fired off from Marketo's servers exactly 32 seconds before the "recipient" (or the intended recipient's spam filter) clicked? This particular example was also telling in that the "Email Delivered" activity occurred at 19:47:04, so the click was registered prior to the delivery. But do we even know that these events are registering in the correct order? Can the timestamp in the activity log be trusted?