Hi Julian,
If your idea is easy to replicate, I recommend not accepting their offer even if it sounds like free marketing. But then again, maybe you don’t even have a reason to advertise.
Keep in mind that there are lots of copycats out there who are pretty good at replicating and hitting the market fast. Public disclosure is so risky before having the patent because you’re just giving them months ahead of you, and before you know it, the market is saturated and you didn’t even get to production.