Thanks for your input sdsinc.
Here is a copy and paste from Morgan Linton.
Sorry but with all respect due I think it's bullshit.
It's stupid. It's like saying you have the best of both worlds because you have .co + .com. Nonsense.
If you blindly follow that kind of advice you will lose money, and you will have to 'unlearn' the nonsense before you get back on the right track.
To keep it simple: .co.com is a private subdomain, just like .gb.com, uk.com.
It's not like .co.uk, .com.au, .com.tr, .co.ug and the countless ccTLDs available at the third level (.co.cctld).
It's not a real extension, it's just a private subdomain.
Have you seen any sales ? End user adoption ? Getting traction somewhere ?
Why should anybody invest in .co.com ? Why not gb.com or .uk.com then ?
Just to be clear, you are free to use a .co.com for your business although it's a bad idea (possible typos and unnecessary confusion among your clients). But don't expect that you will be able to resell them.