Theyre also on Boylston street, near the Pru, and all around Fenway Park.
They're from a local company, and the city started a trial with them a year or two ago. I guess they liked it, because I see them in more and more places. They have two models, a large green one, and a smaller black one for places like the north end.
The city of Boston is "encouraging" local businesses, health care instutitions and higher ed to fund the Big Belly's. In my personal opinion, it's a curious arrangement for those who have permits or plans pending city/BRA approval, and the Mayor's office "suggests" they drop $50k to "sponsor" 15 compactors.
The city wins twice: they don't have the initial cost of the unit, and save on labor costs over the long run.
Also, it was the Back Bay hysterics who initially pushed Seahorse to redesign the compactors to better fit into the "neighborhood aesthetic" or some rot.
I personally find the machines revolting. I'll stick trash in my hip bag before I ever touch one of them to throw out a candy wrapper.