Inspired by the idea of okigusuri (置き薬), which is an old Japanese method of selling medicine, confectionery companies have begun marketing a new service targeting businesses. Okigusuri entails leaving a box of medicine and medical supplies with a family at no charge, hence the practice's name - 置き薬 literally meaning something like "left medicine." At set intervals, a company representative comes by to check the boxes, replacing anything expired at no cost and charging the household for anything that has been used. This business model is called senyokori (先用後利), meaning "use first, pay later." There's a much more detailed explanation at the Japan Times.
Recently some businesses have begun hiring confectionery companies, local farms, and other distributors to stock snacks and cheap meal items for employees. Rather than 置き薬 ("left medicine"), these are called 置き○○ ("left" fill in the blank). For example 置き菓子 ("left snacks"), or more generally 置きビジネス ("leaving business"?).
This doesn't seem to normally be a free service - customers are expected to leave money in a little box (it's difficult to see below, but those frog heads "eat" the payment). But it looks like these refreshments are usually reasonably priced (one IT company in the segment only stocks items that cost 100 yen each - about $1), and it saves employees from having to leave the office to grab something to eat. Personally I like to get out and stretch my legs every now and then, but if you're trucking through something important and can't spare the time but need your sugar fix, this sounds like a nifty solution.
This is definitely an interesting marketing strategy, and I imagine it's a lot cheaper than what a distributor would spend to set up a vending machine. Although free snacks would be a much better perk for employees, I could see this lifting morale and perhaps improving productivity within client companies.
Update: A friend of mine brought this article to my attention, which mentions that this service goes back to 2011, and that Glico started selling its ice cream this way in offices after the 2011 Tohoku disaster prompted the Japanese government to enact power conservation measures. Offices were hot, and ice cream is cold!