We should be all means ask other companies to link to OpenACS but not require it. The OpenACS community benefits as a whole when the number of people using the system to build production websites grows. As a new user, if I see 1000+ production sites built with openacs.org I would be more compelled to look more closely at the toolkit.
One idea is for the OpenACS.org site to promote in some way the sites which provide prominent links back to openacs.org while still allowing anybody to post that their site was built using this toolkit. The implementation could be as simple as ordering the links on the OpenACS Sites page so that those which link back to openacs.org get listed first. Maybe these friendly sites get highlighted in another way or promoted randomly on other pages within openacs.org.
Another idea would be to create a portlet on the openacs.org home page which randomly highlights one of these friendly sites e.g. "Today's featured site built with OACS". This would provide relevent content for openacs.org while providing much higher visibility to sites that link back to openacs.org.
As a concrete example, http://www.transparentnetworks.com is a very simple, mostly static, site which was built using OpenACS 4.5. The company doesn't care that it is using an open source toolkit but it is still important, imho, for others to see that OpenACS was chosen as the platform for yet another company's web presence.
-Mike
