With the rise of sites like Craigslist, I think they're almost a thing of the past. I see the occasional yard sale sign around, but I remember more in the 90's.
I use craigslist a tonne. I've never gone to a garage sale: I work weekends.
Well, maybe that's hip Vancouver but New York State's Southern Tier is at least a decade behind the times (in some ways, it's probably five decades behind but that's for another thread), so garage sales are plentiful in this area. Since this week is "Spring Clean Up" by the Board of Public Utilities, private garage sales and church rummage sales sprouted like dandelions on Friday and Saturday (the 11th commandment, Jamestown and environs style, is "thou shalt not hold garage sales on Sundays").
I held a garage sale once, and my motto is, "Never again!" To make it "worth it" to advertise, two of my girlfriends joined me. Since it was at my house, I had to rearrange the garage or empty it out to make room, including moving my gardening/lawn equipment out to the yard (understand I have a lawn tractor, two lawn mowers, a snowblower, a rototiller) plus some other bulky stuff like a large, non-folding dog crate, several sizes of "have a heart" animal traps, and a portable air compressor). They helped me set up tables and make more tables by using plywood on sawhorses (both supplied by me). After spending two days selling stuff, we had to pack all the unsold crap except books into my vehicle (I had an SUV, they had cars) on Saturday afternoon to take to the local humane society thrift store. One of my girlfriends packed up all the books and hauled them off to the public library to be sold at their big used book sale. Now, with rain threatening, I had to take down tables to have room to put all my stuff back into the garage.
I made around $75. If I had made 3 times that, it would not have been worth it to me. Now, I just donate my stuff. I donate my time, money, and goods to local organizations/charities because it's the right thing to do and because I support their programs/purposes, not because I can get a tax deduction.