Congrats Bill! I remember getting the $100 credit line increase a while back as well. I was surprised to find out later that not everybody gets it. I think it has to do with how much you use your card. It was my only card back then so I used it frequently.
I have another card with cash rewards now and don’t use my Capital One anymore (just once every couple of months or so to keep it active). I haven’t received any other line increases since then, but I sent an extra deposit a few days ago. I want to show a couple of years of good payment history and a decent credit line for this card before I close it next year. I just don’t see the point of keeping it anymore.