I think the same spam has shown up under 3 or 4 different screen names in the past week.
Same list of phones, pretty much the same titles, same company info.
I'd think that the return on making multiple accounts would be much less than the return from posting their spam (which is likely exactly zero).
BTW: Do not reply to their threads. It only encourages them.
Open the post, use the little triangle to report it, click on their screen name to find & report their other posts, then leave them alone.