Is Link in Lieu of Payment From Education & Non-Profit Sites Acceptable?

Imagine Company X provides a service. X is nice enough to offer it for free to education and non-profit sites. However in exchange for the generosity ACME demands that education & non-profit sites place a link on all of their pages to two of X’s main products. Would you consider that a link scheme which is in violation of Google’s Webmaster guidelines? Think carefully before you answer for you may be surprised.

The company in question (Automattic, creator of WordPress) specifically states:

Free option

We can provide an API key completely free of charge for selected non-profits in exchange for some promotion, specifically links to WordPress.com and Akismet.com on each of the protected blogs. What’s required?

* A link to akismet.com on every page.
* A link to wordpress.com on every page.
* Contact us with your key and website after you’ve added the links, so we can check the links and mark your key so it doesn’t trigger our anti-abuse systems.

Here is the code for the links:

<a href="https://akismet.com/">Protected by Akismet</a>
<a href="https://wordpress.com/">Blog with WordPress</a>

Do you see a nofollow anywhere, cause I don’t. Also the link is not optional (as in out of love or gratitude), it is compulsory.
However Google Webmaster guidelines state that:

Not all paid links violate our guidelines. Buying and selling links is a normal part of the economy of the web when done for advertising purposes, and not for manipulation of search results. Links purchased for advertising should be designated as such. This can be done in several ways, such as:

* Adding a rel=”nofollow” attribute to the tag
* Redirecting the links to an intermediate page that is blocked from search engines with a robots.txt file

Is this a link scheme? I am somewhat confused as it is being openly done by Automattic, a well-known company behind popular WordPress software. Are the rules different for WordPress than for the rest of us?
What do you think? Matt?