When you go to the ClickBank marketplace and click on a category, you'll see some options for screening and sorting different products to shop for, or become affiliates for. There is a filter for $1 trials, which should show you such offers once checked.
I clicked that and one of the sites which came up is Coffee Shop Millionaire. Like many CB products it gives a video presentation and but this one makes you watch the whole thing before giving a link to the shopping cart. It does not have a $1 trial offer, at least not anymore. So, I ended up leaving the website and I ended up having this dialogue with a "online live agent."
So, its powered by a service called IntelliChat, which is meant to try and keep the visitors on the site and make a purchase. Not a bad idea, if the agent isn't human you won't be paying by the hour and it can still get a message across.
CoffeeShopMillionaire is one site which shouldn't have come up in the results that I selected, and Affiliate Cash Snipers is another one. It has a 'free trial' for the 'most advanced sniping topics', however, as seen on its order form.
Not to say its not worth browsing ClickBank products for one dollar trial periods for affiliate products, in fact it is worth it. But CB needs to fix that.