Has anyone else noticed Marketo suddenly (past two days or so) catching a lot of duplicate leads, but the leads identified as duplicates have unique email addresses? I've found 3-4 of these since yesterday morning. One I merged but the others I'm not confident are duplicates. I have never seen Marketo catch duplicate leads based on anything but email address in the past, so I'm wondering if something changed on the Marketo side recently, and if this will be a problem going forward.
Marketo hasn't changed the default de-duplication field (Email Address), but if someone requested an additional field for your instance, then that may explain it.
Also, when looking at the lead records for the duplicates, is there any evidence that the email address was changed after the lead was created? The reason I ask is because this is a common thing I see. A new lead is created because, at the time of creation, the email address field doesn't match any other record, but then later the address on either record gets changed to match the other.
I don't think that adding a field would cause duplicates as that would imply the new field plus email address would be the duplicate criteria (email address is always a required field to identify unique records). It must be that someone is changing email addresses.
Actually, the more fields you add to the equation, the more likely you are to get duplicates. It's because every field used to de-dupe has to exactly match any newly submitted data, otherwise a new record is created. More fields means more chances that a lead will fill out a form with a different name, or address, etc.
I should have said duplicates being found. The more fields you have the less likely you will have an exact match. I see what you are saying though, if you have more fields then the same person can appear more than once more easily.
No we haven't added any new fields recently - I have noticed the messaging in the activity log for these leads has changed though - not sure if that's relevant. It used to read that there was a duplicate, and now it reads "You may be working with a duplicate record". I got another one this morning and there is only one lead with that email address, so it shouldn't be identifying any duplicates if it goes solely on email address. There are two other leads with the same name but those two are duplicates and were not caught. This new one is from a different company, but same phone number (I assume she changed jobs and we would want to keep these as separate records in our CRM)
I wrote up a post on how to best troubleshoot duplicates here
I've also looked at your instance to see if there were any additional fields being used for dedupe, but it's currently just the Email Field. If you're not able to determine where the dupes are coming from after reading through the article, feel free to open a case with support, and we'll be happy to help troubleshoot.