Not silly at all!! I've given out magnets back in the late 90's..with my old company name on it and I still get calls now and again.
ONE word of advice.. DO NOT MAIL the magnets.. EVER. People don't realize but they can erase computer hard drives and some smart phones, that wouldn't be a great first impression. I know a biller who got a call from an irate office manager because the magnet in the envelope laid next to her phone and erased her phone.!
When I did a trade show or seminars, I gave away clear clipboards, I had transparent business cards made and I laminated all the clip boards with these laminated biz cards and my logo. They were a huge hit. I bought them bulk and then I had the cards printed on transparent backing, just peel and stick