Wow super awesome advice! It's so refreshing to hear these creative solutions, and so quickly. I've spent days or weeks in the biggest chains with support and Marketo engineers without getting anywhere (other than our current brute force deduplication) for years, so thank you thank you thank you! I like the idea of using a JSON array too as delimiters seem pretty brittle and inexact 
The only thing we can do with the loopback method is to post a form, right? Basically we can only update fields or pass in a Munchkin cookie via _mkto_trk, but we can't merge things. If so, I like this idea for saving API calls on lead updates and we could easily set up a reverse proxy, so I think I'll look into that in case they block the instance hostname (which if I understand right, is now required instead of localhost).
That form hack is pretty darn crazy, but it definitely sounds like it'd work. The bummer there is that it makes form logic very convoluted (and hard to debug for eng and marketing), and makes direct form events useless for things like lead scoring, or triggering an email. I could imagine that we store the name of the form in a custom field (perhaps as a JSON array in case there are multiple forms submitted quickly), send that to the webhook, have Salesforce write that to a lead, and have a separate trigger that looks for that custom form name field to be on a new lead, or updated on an existing lead, but whew that's messy. You sound pretty familiar with the ins and outs of Marketo though, so if that's your suggestion, I trust the advice much more just anybody getting that creative.
Overall, are you basically saying that we should never create any lead in Marketo and funnel everything through Salesforce?
It seems like this implies that we can't import lists into Marketo either - at least not without making sure all the leads are in Salesforce AND synced back to Marketo already. Is that the idea?
If so, this seems like a pretty dramatic change for us, but I could see it working out. Using the forms API instead of the REST or SOAP API to associate the cookies after the leads are synced from Salesforce to Marketo seems like one of the key tricks here.
Without that trick, it seems like we'd need to call the REST API once per pre-Salesforce-to-Marketo-sync session, and would therefore have a limit of creating 10k new leads per day (or fewer with multiple sessions), which isn't enough for us.
It seems like it's impossible to use the API for anything that might apply to many leads at scale, which seems to indicate that we can only use it for reporting or occasional things. This a quite a bummer since with Salesforce you can add 10k API calls for ~$20 / month, and use bulk API calls to do 50k things at once, whereas with the Marketo REST API, it seems like many operations are 1:1 and this person said it costs $15k / year to simply add 10k API calls. If I'm getting that right, that's madness!
Anyways, please let me know if I'm saying sane things, and thanks so much for your help!
.png)
- Copyright © 2025 Adobe. All rights reserved.
- Privacy
- Community Guidelines
- Terms of use
- Do not sell my personal information
Adchoices