I can give you guys a lot of logic for why the policy is what it is, and I can tell you the parts of it that have less logic also. But the policy is what it is and everyone needs to respect that. In some sense I had a role in crafting the bulk purchases policy, so I can answer for how it came to be.
I do so so that the information helps members understand, not so that there are two hundred replies disputing my thoughts and insisting on a reconsideration and a change.
The site, from its owner, has a no-decant-exchange policy on the public forums. (I'm afraid we're sort of end-of-story here. That's the policy.) The policy makes clear that fragrances exchanged here have to be in standard manufacturer's bottles only. Standard manufacturer's bottles only. No decants.
However, some manufacturers make their products available in very large--bulk--quantities, at substantial discount when cost-to-quantity ratio is examined. Those are really nice manufacturers. When they make these large amounts available, they almost always do so EXPECTING themselves that the liquid of these large amounts will be poured into smaller bottles that will make application to bodies easier. For example, they sell their bulk amounts in screw cap splash bottles, say, expecting that they'll be poured into smaller atomizers. Great. So the manufacturer's already know their juice is going into a different bottle. The Basenotes "standard manufacturer's bottles only" stipulation seems to apply less strongly for these bulk purchases as a result. But only for these bulk purchases.
A most important point behind the existence of the bulk purchases policy: those bulk bottles are still damned expensive! Damn! Costs so damn much to save money--sure the cost-to-quantity ratio is mega savings, but only because there's so damned much quantity. Blast! I still can't affort that--cripes--and can't even use all that bulk. Call Dr. Kevorkian, I'm ready now.
Where else is there to go to find fellow cost concerned fragrance lovers who have the same interest I do? Where can I go and find people to share the price and the BULK with me so that we can all be happy, smell kick ass, and still buy drinks when we get to the bar with our new scents on? Basenotes! It only makes sense that members would find each other HERE to combine interest in bulk purchases. Who are we kidding? There's no way the site would want to get in the way of such wise consumerism. So it's permitted even though the bulk is broken into bottles that are not standard manufacturers bottles.
No smaller than 50ml. A poster above complains that that size is arbitrary. Another poster above complains that that size kills extrait or straight parfum bulk purchases. I'll deal with both.
"Arbitrary." Not entirely, but there is a measure of arbitrary to it, yes. There are two reasons why 50ml is the cut off. First is out of respect for the "standard manufacturer's bottles only" stipulation. Standard manufacturers bottles are usually 50ml or larger. We make the cutoff at 50ml out of respect for that standard measurement. Thus breakdowns of the bulk are done in amounts that are standard. Whoa, wait a minute, there are lots of 30ml bottles out there, mister, lots of manufacturers make a standard 30ml so how about that? Why can't I already? Why not fix the limit at 30ml since the almighty industry does, hunh? Here's the reason: because we need a cutoff and we need an across the board standard one and we need to come off a bulk purchase, and we fixed on 50ml so we wouldn't get whittled down to 25, to 20, or down to mere decant size. Go ahead, complain about the arbitrariness that's the result--we, or I, picked 50ml, I picked that number instead of a lower number. But I didn't pick 50ml because it was a donkey's rear and I put the tail on it blindfolded. I said 50ml because 50ml is the USUAL small size available in standard manufacturers bottle sizing. Some go smaller, but not everyone does. Some manufacturers go smaller, but at Basenotes the policy is bulk purchases are broken into divisions no smaller than 50ml.
Now the second reason: anything smaller comes closer to looking like decant sales. What's the difference between 25ml and 30ml, Mr. Mod? Come on, man, I'm trying to break it down even-steven and I want to sell 4 divisions of 25ml instead of 3 of 30ml, which will leave me stuck with 10ml and out that money, dude. Come on, no fair! This is the last 100ml of my big bulk purchase, jeeeez, and you've got it in for me, breakin' my balls when I'm just trying to be a good guy with 4 of your members who want to buy, isn't that rich!
The second reason is that the smaller the division, the closer it is to decants, and would thus be a way around the words of the no-decant-exchanges policy. 50ml is the bottom limit. This site's marketplace exists for friends to make advantageous exchanges with fellow members, not for volume profiteering, volume selling, or volume distribution. Inconvenient if you want smaller amounts, yes, but in that case this marketplace isn't for you.
The bulk policy is for ten friends, let's say ten for an example, to get together and get 1000ml, let's say. They arrange in advance and the divisions are all spoken for. That's also a rule of the bulk purchases policy. No member can use the public boards to make a bulk purchase with only a couple fellow purchasers, and then use the boards to sell off remaining divisions to not-yet-found purchasers. You can't make a purchase of 1000ml yourself and advertise that you'll sell off the other divisions now that you've got the bottle. Size doesn't matter here, as that starts to look like sales of decants. All divisions of bulk purchases need to be arranged in advance of the purchase.
No division of a bulk purchase can be offered for re-sale or exchange on the public boards of Basenotes. Aw cripe, whadda ya mean? I bought the thing here, I guess I don't like it enough, and I'm trying to sell exactly the same bottle to anyone else who wants it--and someone is gonna! Jeeez! Sorry, now it's not a bulk purchase you're selling, and what you're selling isn't in the standard manufacturer's bottle, so the standard manufacturer's bottle stipulation applies. Because you bought it in a bulk purchase here doesn't mean you can publically re-sell it here if you don't like the scent. Sorry, that's the way it is. I guess if you buy at the discount that comes with joining a bulk purchase you take your chances.
Now about Aiona's fine point of how the 50ml cutoff puts a crimp in extrait deals. Let me first say that there aren't many bulk purchases here at Basenotes. In fact there seems to be more questioning of the policy than purchases of anything it is meant to govern. Indeed the policy was made with eaux de toilette sales in mind. All of the bulk purchases in question have been, although in one case a member might have been seeking to sell some edp under an understanding of the policy, I can't remember for sure right now. Anyway, yes, guilty as charged, the ml counts are done with edt in mind as that's the traffic in almost every case.
It might still apply to a bulk purchase of 30ml of extrait--it would depend. If we thought the manufacturer expected the 30ml of extrait would be broken down into divisions before use like we expect of a manufacturer selling bulk purchase of 1000ml edt, then maybe we'd allow that bulk purchase of 30ml of extrait to proceed. Maybe not though, maybe most likely not, because 30ml of extrait can still be a standard manufacturer's bottle intended for one person's use from right out of that bottle. IT WOULD DEPEND. We'd look at it on a case-by-case basis. What we wouldn't do, however, is throw our hands up in the air and say, well, since we could break down a bulk purchase of 30ml extrait into 3 divisions of 10ml each, well then, I guess we can't say the same can't happen for edt bulks, and why not have everyone selling whatever they want in 10ml bottles of their own choosing. And heck, why not chuck this ladies-and-gentlemen-agreement thing about needing all the divisions spoken for in advance of purchase? Why not just have everyone selling whatever they want in 10ml "splits" and why not let them do so out of all the 50ml and 100ml bottles of whatever they have already? I guess since extrait can conceivably be broken down to 10ml bottles, that breaks down everything, and golly, I guess we'd have to let the edt selling partisans use that size too. So, shucks.
That would make meaningless the very direct no-decant-exchanges policy. The bulk purchase permission is not a back door to decant sales and exchanges. If someone is going to try to arrange a 100ml purchase of extrait and wants to do it as a bulk purchase here, heck, we might be entirely with you. All you'd need to do is ask and if we're okay with it it would be easy to put a note in your sales thread that the bulk purchase of this extrait was permitted. All it takes is asking.
Also I defined a bulk purchase as 250ml or larger. 250ml is the bottom limit for what a bulk purchase is. (I said that twice now but it's late and I'm forgiving myself for that and all other editing and grammatical mistakes.) You could say that's an arbitrary cutoff, and to some extent you'd be right again. But the situation needs a cutoff, and if I had allowed the cutoff to be at 100ml, or 120mls, it would again make meaningless the no-decant-exchanges policy. 500ml seemed high as a minimum cutoff, and a member brought to my attention that he wanted to do bulk purchases of bottles that the manufacturer made available at 250ml. (Five divisions of 50ml, he said.) So I said 250ml seems like a good, round number, it even sounds pretty to the ear. I suddenly liked that for policy. Done! Fiat 250ml minimum cutoff, obey!
Oh yes, but different strenths of fragrance juice should command different division minimums and different minimum cutoff definitions I hear. In some measure I'm sympathetic to the plight, but in some measure I'm not--too much to think about, in a sense. Oh it's an edp you say? Hmmmm, that would put it right in the middle between edt standards and extrait standards, right? Hmmm, let's work up some different ml measurements then! Hogwash. It's late and it's making devils in details. We'll consider exceptions to the policy, all you need to do is ask, because in a sense the bulk purchase policy is itself an exception to the no-decant-exchanges policy, but the bulk purchases policy, and its weaknesses--its frustrations rather--are not a way around or a step to elimination of the no-decant-exchanges policy.
It's late and I'll try to remember to edit and spell check this post tomorrow. I've been very hard on Aiona who does ask a spectacular and justified question above, and I publically apologize to her for that now--my rhetoric goes beyond the mere explanation that I could have done. Sorry, Aiona, you're kind of my straight guy in a comedy routine here--I've only been extravagant to get a point across to many readers, and have no wish to disparage what is an excellent and thoughtful point.
Best to all, but this is what the policy is.