Same PO BOX Address on different sites

If I have the same PO box address at the bottom of my different sites which relate to the same subject, would this hurt my position in the SERPS?

I'm thinking the Google may demote me because they have the same address. Would this be correct?

I've seen several examples of high profile serps where 3 or more of the top 10 sites have the same physical location addresses and company names in the site footers.. so going by that it wouldn't seem to matter.. at the moment.

Is anyone aware of any indepth research and testing that anyone has carried out?

Okay thanks for your help, but like you say "at the moment".

It might be worth thinking ahead for me.

Well I can't see into the future, but it's an obvious thing that an engineer at Google might one day thing.. "hey, heres a way of potentially spotting related sites"

I personally wouldn't do it, but then i'm uber paranoid and like to keep my sites completely unconnected, I wouldn't want to see them all penalised at the same time!

Not like that just on the basis of PO box address because it is not related with the subject or theme of the site, Not be taken same as duplicate content.

In my opinion you don't have to worry regarding that but take care of your site related content duplicacy...

I don't think that can ever matter, here is why.

1) If it were true, then several sites that sell the same model number would get penalized. Eg: Nokia 5100.

2) If it were true, rouge competitors would put up lots of sites with duplicate infromation.

That being said I think that the physical location and address could effect thigns because these are more deterministic. Still though a rogue competitor could take advantage of the fact. I think the location helps for Geo Targetting but is not likely to have a negative effect.

Its good that you are thinking on this level but I don't believe it will cause you any problems now or in the future.

Ok thanks again for the advice, it's very much appreciated.

Google is not in the business of promoting or allowing equal competition. they are in teh business of providing the most relevant results for a given search term.

That being said it would not makes ense for them to find out who owns websites and only allow one site from each owner to do well.

If the sites are relevant to their terms according to the algorithm then they shall rank.