To each his own. The bottom line is, if you're going to geocache, know the rules. If you're not into leaving swag, that's ok, you have nothing but the log book to sign. For our family, personally, we enjoy the hike, the adventure, the find AND the swag. I keep a swag bag in my car and put a lot of thought into a swag I would leave for the next geocacher, just my style....carabiners with compasses, new small flashlights w/battery, small micro tools, pins, foreign, interesting coins, cool rings, interesting trinkets, small mirror compacts, usable items, keychains, etc. I buy new things in bulk (buy for cheap), at dollar stores, thrift stores (great places to pick up swag), freebies from online, giveaways from stores, etc. I want the next person to find a nice surprise and try to carry something for everyone. Once I find the cache, I evaluate what's inside and leave something different than what's in teh container.
Today, I found 5 caches. Four of them had nothing but junk and garbage; broken crayons, pieces of plastic, used broken erasers, rusty paper clips, etc. I was truly disappointed, but at least happy I found the cache. I wiped out the containers, replaced bags for log books with new ziplock bags, threw out trash, and left a few usable, worthy, and thoughtful swags that I know someone would be happy to find. The other cache I found today had a dollar bill, and other neat swag inside, it was still a newly placed cache.
I am thinking of copying a message and leaving it in every cache, as the original poster stated: CIJO - Cache In, Junk Out...Obey the rules, trade equally or up.... Something like that, so others can be mindful of others.