I mostly agree with the sentiment of this post, though it seems over the past couple of years the "dibs" get thrown around a little too freely. If sellers need to adhere to a "dibs" system, then for sure the "dibs" better mean something. I've seen enough occurrences of a member throwing down "dibs", only to come back a while later and release them after reading the actual ad.
It has to go both ways for the system to work. Calling "dibs" and then releasing them isn't really much different than cancelling an auction that has bids on it, but only one of those is a ban-able offence.
I threw up a little every time I typed "dibs"