I find it amazing the creativity people have, especially when being frugal. According to SPRANQ creative communications (Utrecht, The Netherlands) your ink cartridges (or ink toner) could last longer and therefore they developed the ecofont. Spranq claims possibly 20% longevity gain in your toner cartridges.

At print size, for your typical documents, it’s quite a decent font and legible. It won’t save the world, but it just goes to show that the smallest, most inconceivable thing CAN make a difference!!