Short answer is it depends… in SEO nothing is black and white except the hats. 😉
In general, .ORG does NOT carry any more weight than .COM. To test this, do a search for a variety of search phrases. I would test about ten to get a good statistical data but less will give you a good idea as well.
Go ahead, we’ll wait….
What percentage of the results are .COM? .NET? .ORG? .GOV?
Percentage wise, I am sure you will find that .COM did better. Naturally, there are more .COM domain names with active sites so it stands to reason that there would be a higher percentage of .COM in the results but even when you take that into account, you still get a larger percentage of .COM most of the time. So in general, the answer is no, .ORG does not carry more weight.
But wait a minute… did you notice that the percentages changed based on the search query? Now we are back to “depends” and here is why…
Certain terms do better with certain TLDs because the search engines do a pretty good job at weighting the likely hood of the end user finding relevant content on a given TLD based on the “theme” and/or segmentation of the search phrase.
For instance, a search for “housing” on Google pulls up mostly .GOV and .EDU TLDs because most searchers looking for “housing” are searching for housing assistance or student housing and .EDU and .GOV websites would provide the most relevant results.
So as stated above, in general, no a .ORG does not carry any more weight than .COM. But when you look at specific search terms, it very well could rank higher because the search engines might have those terms more closely associated to the type of content that would be found on a .ORG site.
So is .ORG the right decision for you? It depends on what the search phrases are that are relevant to your non-profit. Are those terms more associated with .ORG than they are .COM? (yes, run the test again using those terms.) If you find that those terms have a higher percentage of .ORGs in the search results, then you might find SOME benefit in the .ORG domain name. Again, nothing is black and white in SEO except the hats.