Might mean an offer, but more than likely not. Just wanna get to know him a little better and him to know them too.
Just to give you a little data, my 2011 who ended up with multiple offers was invited to 'unofficial' campus visits at least 5 different times. None of them resulted in an offer during the visit. Two did end up resulting in offers at a later time and I believe the other 3 would have too if he hadn't liked the first 2 so much.
All of those visits did include nice campus tours, football/basketball games, Q&A's with current players and meaningful conversations with the head coach. On a couple of them, other 'invited' players were visiting too. I liked that...gave us an idea of the types of kids being considered.
Exciting times for sure, but try and relax, enjoy
...they like him. Thats what it means for now.