The co-op surely ordered from a hatchery. My local co-op always orders pullets unless they're meat birds because they know that's what most of their customers want! And normally, if you get pullets from a hatchery, they are actually pullets.I'd be reluctant to buy chicks from T/S, but I did purchase 20 chicks from a local farm co-op that were advertised as pullets, simply because they had the breed I needed and I didn't know where else locally to get them. I assumed (based on past experience of buying off of Craigslist) that 40% or so would be cockerels (that I would get rid of), but no, was I ever surprised. They were all pullets. And they have been excellent chickens, even though I'm now swamped with more than I wanted.
Most of the TSC issues are probably because they order a lot of straight run and then do a terrible job labeling.
The problem with buying off of Craigslist is identifying the dishonest sellers. Well, that and a bunch of You Tube videos on sexing chicks that make people think they know how.
