AFAIK they don't. There is a cap on licensing for H264. Cisco is already hitting that limit with their commercial offerings, so they can essentially offer OpenH264 at zero (licensing) cost.
Supposedly offering OpenH264 ended up costing Cisco more money in licensing fees. See Monty Montgomery's blog post from 2013 about the initial announcement of OpenH264:
There are a couple of comments in the comments section titled "Cisco's Costs" in which Monty says that someone he knew at Cisco told him that they had been under the licensing cap and that the OpenH264 project would increase their licensing costs.
Cisco is also a h264 patent holder, which may have given them a better licensing deal.
Beyond this, Cisco is part of the 'Alliance for Open Media', consisting of Google, Cisco, Intel, Netflix, Amazon, Microsoft, Mozilla (the latter funding Daala) who are building a new royalty free codec for their needs based upon vp10, but which will make use of any useful technology their members have access to.
