Wdym by training own model? Do you mean setting up a workflow to catch the signals?
I think the answer lies on what kind of intent you're looking for, platforms like Bonbora has partnerships with other companies where they share user data with Bambora, you won't be able to access those with your own system.
But if they're public like job changes, news, reviews, job postings and anything available in the public internet, your own system will work better