The homogeneity of fragrances in the marketplace is markedly poignant, especially lately. If you have shopped for perfume yourself (and who hasn't) you have surely noted it, despairing at the lack of what could be different enough to jolt your senses into a eureka moment. It seldom happens. If you have followed out Twin Peaks articles comparing smell alike perfumes you are equipped with solid argumentative aces. Back in 2008 I had devoted space into why it's so difficult to protect a perfume formula as a unique intellectual property with all rights stemming from this and why formulae are copied, more or less.
There are reasons however that are increasingly more relevant than just the historical explanations or the "shooting" of the scent juice that goes on behind closed doors. Those reasons have to do with both marketing research and with chemical intricacies going on in the laboratory. Let's take them one by one.
How Perfume Marketing Tests Work
Modern perfume development for the mainstream invariably involves focus groups. Each perfume "draft" is presented to a randomly chosen public segment, stratified according to their social status. But they are not presented with the draft free to comment on it the way an evaluator works. There is no free association or technical comments, if only because there is no specific knowledge of how to go about the latter and the former would be practically useless and highly individualized anyway. Instead people are presented with a couple of fragrance "mods" juxtaposed with a benchmark perfume that has been performing very well in the market for some time (an Angel, a Tresor, a Dior J'Adore, a Cool Water...). They fill out a predefined questionnaire which will further dictate the twists in the formula that the evaluators will demand of the perfumer. This is why best-selling/popular perfume lists based on market research are somewhat skewed to begin with, exactly because they commence with certain givens within the parameters of which the subjects are allowed to move. This is why so many fragrances smell like tiny variations of the exact same design.
And because time and financial pressures are huge, often the direction of the perfume (the "brief") is given not to one team headed by a single perfumer, but to many, in different companies. If each of them modifies a small part of the whole, then more than one perfumer takes credit for the finished product. This is you end up with not knowing who masterminded what, which in a way devalues the artistic authorship.
The Ubiquitousness of the Same Raw Materials
One can complain about the endless tirade of pink pepper or oud in the listed "notes" of any given perfume press release, but the truth is that the notes list bears little resemblance to what actually goes inside the perfume formula ingredients-wise. Basically no more than 20 manufactured raw materials (natural-identical or synthesized anew) get recycled endlessly. These include citronellol, phenyl ethyl alcohol, hedione, heliotropine, ionone, methyl ionone, hydroxycitronellal (despite the IFRA reductions it can still be used in very small amounts), coumarin (ditto), Lilial, salicylates, patchouli, Iso-E Super, synthetic sandalwood, vanillin, synthetic musks, and ambroxan. They potentially have the ability to build diverse "effects" when put into context, but the reason they're preferred has to do with two very important reasons.
One is their unchanging nature; they are stable, technically dependable materials, linear, practical and always of the same quality standards (unlike the wavering quality of natural materials or less stabilized ones which are making their way out of the perfumer's palette as we speak). Therefore they're produced in gigantic quantities and supply dictates usage. They have effectively become perfumers' currency.
Not only that, but the vast supply and subsequent widespread use means that the public has been accustomed to them via familiarization; and familiarization, in matters so inextricably tied to memory and emotion as smell is, means that the public seeks them out again and again.
A vicious circle exacerbated by the avalanche rhythm of fragrance releases in the last decade.