No, it shot to popularity because it functioned exactly like SMS messaging, except that messages were free. "Fooled users" is an incredibly mean-spirited way of

No, it shot to popularity because it functioned exactly like SMS messaging, except that messages were free. "Fooled users" is an incredibly mean-spirited way of looking at it - iMessage certainly "fools users" into thinking it is SMS far more. Users care about the result, not the method used.