I recently declined an offer from a company and the recruiter is asking me why I declined and where I’m heading to next. I’m wondering if there’s any benefit (or harm) to disclosing this info? I would love to talk with them again in the future but I don’t think this company is the right choice for me at this moment.
There is no harm in disclosing this information after the fact. It's helpful feedback for the recruiter, and it builds rapport with them for the future, as you said. They may ask you WHY you chose a different company, though, and if you can say something constructive, that's also useful.
In my experience, it's often about compensation. And that's OK to share as well.
Great question! I have two tactical thoughts:
It's actually quite common for the recruiter or hiring manager relationship to continue after an offer rejection, so you should absolutely take the time to circle back and be gracious in your decision.
Start by saying thank you for all their help. Then focus on things that are unchangeable about the company, e.g. size, type of work, a specific person you are able to work with at the other company.
If it's a compensation issue, take a look at How do I reject an offer politely because the compensation is too low?