Well maybe you should consider some technical facts:
Iridium is a precious metal that is 6 times harder and 8 times stronger than platinum, it has a 1,200°(F) higher melting point than platinum and conducts electricity better. This makes it possible to create the finest wire center electrode ever. Prior till now, spark plug manufacturers have favored platinum for their long life or performance spark plugs due to its high melting point. However platinum alone is no longer enough, ultra long life spark plugs and smaller center electrodes required harder and stronger precious metals. The strength, hardness and high melting point of iridium makes it very well suited for a fine wire plug and for ultra long life spark plugs.
Don't think you want to compare these to copper !
Like I said before, these Iridium Plugs looked like NEW after 110,000 miles in my daughter's Malibu Maxx. I have never seen used plugs look so good !
Iridium Plugs are now standard in Corvettes.