An Acronym for Total Cost of Ownership.
The total cost incurred by all aspects of ownership and operation of a particular item in addition to initial capital outlay, including such factors as administration, maintenance, licensing, updates and end-user training.
Such a figure is always difficult to obtain and disputable, thus TCO is a term mainly (ab)used by MarkeTroids, who will always claim that TCO favours their product, even if it would appear to be expensive. This is MicrosoftCorporation's current anti-Linux marketing strategy, after they were forced to admit that they could never be as cheap as Linux.
See also CompetitiveComparisons.
2 pages link to TCO: