“Since every sign creates an interpretant which in turn is the representamen of a second sign, semiosis results in a ‘series of successive interpretants’ ad infinitum (Peirce). There is no ‘first’ nor ‘last’ sign in this process of unlimited semiosis. Nor does the idea of infinite semiosis imply a vicious circle. It refers instead to the very modern idea that ‘thinking always proceeds in the form of a dialogue — a dialogue between different phases of the ego — so that, being dialogical, it is essentially composed of signs.’ Since ‘every thought must address itself to some other,’ the continuous process of semiosis (or thinking) can only be ‘interrupted,’ but never really be ‘ended.’ As Gallie points out, ‘this endless series is essentially a potential one. Peirce’s point is that any actual interpretant of a given sign can theoretically be interpreted in some further sign, and that in another without any necessary end being reached. […] The exigencies of practical life inevitably cut short such potentially endless development’ (1966).”

from Handbook of Semiotics

See also, eg., “blogosphere, the.”