Bot Activity Tracking
I enabled the Bot activity tracking just short of a month ago on our instance, but I am seeing numbers that seem to be lower than I would have expected, with a total of 330 bot activities identified:

For reference, we have had around 240,000 delivered emails, 100,000 opens and 3700 clicks in that period.
As a relative layman I'd take this outcome at face value and just chalk it up as a low impact on our numbers and get back to emailing, however we use a different tool for our transactional emails which seems to suggest a different story.
Our Mandrill numbers show around 70% of opens are by the Google Image proxy email client, which I would have assumed is bot traffic since it is not a user initiated action.
I have read some REALLY old discussions in the community that suggest that the Google image proxy triggers after the first open, which would be great news, but the Mandrill numbers suggest otherwise.
- To those with more experience, does our bot activity seem particularly low?
- Is the Google Image proxy considered a 'bot' by the Marketo bot trackers? (can see a "Googlebot" on a sample of the IAB list, but I'd guess they have a few...)
- Is this even a Marketo issue, or more likely a Mandrill one?
- What other areas or issues could I look into to catch more bots?
Apologies for the long list of questions, I'd appreciate any insights you can share.