Sailthru looks like it has something similar to webhooks (though they seem to call it postbacks?).
I haven’t tried it in Salesforce CRM but I imagine the process will be similar - albeit due to the flexibility of Salesforce you’ll likely need to create custom schemas rather than some of the more generic schemas that are provided via Iglu Central.
I’m less familiar with Salesforce - it sounds like it’s doable but involves a little bit more effort. From what I can gather the approach below should work.
Create an Apex trigger that is invoked on the sObject(s) that you want to capture data for (you’ll likely want to do this on the insert and update events) e.g., trigger accountTriggerWebhook on Account(after insert, after update)
In the logic of the trigger use a HTTP callout to POST the data to your Snowplow Iglu webhook endpoint.
Ensure that you’ve got corresponding schemas for the create/update objects that you want defined in your Iglu repository.