There's a couple of Facebook groups in my area that sell farm-grown products. I've seen ads for eggs there, too - and I managed to re-home a rooster with 3 pullets before mods took it down.
I sell my eggs by word-of-mouth to several neighbors, friends and family members. When we have surplus, an elder from our church comes to buy half and we donate half, then they are distributed to some needy families.
When we first started, I put a big yard sign in front of our house, and got a couple of regular customers from that. I've also put ads on Craigslist which generated a few, but most notable was a chinese restaurant that wanted 30-dozen at a time. Hard to keep up with, and we lost their business. Also a home-based bakery bought a lot, but the distance was a hindrance so they stopped, too. I don't care enough to deliver and we're 30 miles from Kansas City metro area.
Last year, I sold them for $3.00 per dozen. I hated to raise the rate this year to $4.00 per dozen, but after comparing all the expense of feed and supplies to how much money we made, I saw we were losing money. I don't care to make a profit, not at all - the eggs we eat ourselves plus the chickens I butcher and put in the freezer more than make up for the loss. But I would like to break even, so that my eggs and freezer meat are free for just the cost of my daily efforts. I think we may have lost a customer or two, though. It's okay, I'll put the sign back in the yard, maybe visit a bakery or two in our little town, and we should be doing fine.