Teamfox, the community fundraising arm of the Michael J. Fox Foundation, is organizing a trip to the top of Africa. Join fellow climbers of all experience levels, who share a love of the outdoors and the urge to do something good for the world. Visit http://www2.michaeljfox.org/site/TR?fr_id=1180&pg=entry to learn more about the trip and to sign up!

The Michael J. Fox Foundation is dedicated to finding a cure for Parkinson’s disease through an aggressively funded research agenda and to ensuring the development of improved therapies for those living with Parkinson’s today.
We believe without fail that our goal is within reach - but we can’t get there without your support. Please join the fight today.
Learn more about the foundation here, http://www.michaeljfox.org/about_ourMission.cfm

I wouldn't consider this spam. This is information about a climbing activity that happens to be a fundraiser. Where else is there a better opportunity to spread the word than an open forum of climbers?

From the SP FAQ:

"4.1.3 Commercial Advertising

Commercial advertisements are not welcome on SummitPost and are deleted quickly. This includes guiding services and other climbing-related enterprises. Recommendation and/or listing of available guide services on a mountain page does not necessarily constitute commercial advertisement. If you stand to make money from someone acting on your post, it is probably going to be deleted. This includes solicitations for charitable climbs that are in whole, or in part, funded by donations made by others."

According to the posted link regarding the climb,

Participants commit to fundraising $8,000 to get a spot on the expedition. This covers trip costs (lodging, food, transport to and from the airport and park fees) but does not include airfare.

So I think it's ok to post about the fundraising effort as was done in this case to solicit individuals who might be interested in joining the effort. It would not be ok for an individual participant to post here for donations to allow them to climb. The point to consider - is the OP gaining something material from another acting on the post?