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the TLD means nothing in the Google algo
Google will take into account ccTLD's to present different results in local country Googles.
However, since the original poster seems to be contemplating only .com, .net or .biz this obviously doesn't apply here.
(says the person who has had a .org for her own domain for 13 years and regrets never tying down the same .com because now squatters want too much money for it)
.org is not Just for non profits - though a lot of americans think so ( I sat in on some discusions on a bid for .org a while back)
.org was anything that didn't fit the origional structure .com .edu .net .gov .mil
though I agree its a bit sucky to see some didngy afiliate scum site using .org.
BTW .net was intended just for playa's in the networking industry/infrastructure - i can rember when having a .net
address men't somthing (that was back when they attempted to print paper directories of internet addresses)