I define it as having undying brand loyalty or someone letting their excess purchases override their life. I knew someone who bought expensive guns and then whined about how broke they were. I also know they were not bought for self-defense.
When you buy something from [brand] for the sole purpose of showing loyalty to [brand].
This includes sports fans and apple fans in addition to the typical nerd consoomer.
I think that brand loyalty is the major signifier, along with a desire to show everyone else what you bought for social clout. I think that's the case whether it's a practical or a decorative item. You're using branding to say things about yourself, as a substitute for a personality. You and your shithead consoomer friends buy items to make statements about your values, based on that brand's marketing team's ideas of what values those products represent. It's a kind of laziness, letting the marketing teams of massive corporations define your values for you. That's what makes it so obnoxious, hoping that the perceived coolness or popularity of a brand will apply to you too if you show everyone you've bought one.
That's the other big thing that defines consoomerism - the urge to show other people what you have in the belief that owning those brands makes you a better person somehow. Especially if it's something expensive, that makes it a flex as well. Marxists have a phrase for this - "conspicuous consumption" - deliberately making wasteful purchases and showing them off just because you can. Ironically, as we all know, self-described Marxists are amongst the worst offenders for this.
While we tend to associate consoomerism with loyalty to major brands and big corporations, it can definitely apply to small companies as well. The hipster mindset that buying and showing off obscure or unusual things makes you more cool and interesting than having more common things is also its own little corner of consoomerism. I play guitar, and there's a whole cottage industry of "boutique" guitar pedals. Basically what these guys do is buy cheap electrical components from China, slap them together then put them in a "quirky" pedal, and charge a fortune for them. 90% of the time these pedals are no better, or even worse, than the cheaper, mainstream alternatives. But there's this little community of hipster assholes who like to show off their collections of shit "boutique" pedals because they're so exclusive and rare and they think they show what a free thinker they are (whereas it actually shows their lack of critical thinking skills). I'm sure there's similar shit in whatever your hobby is. People want the thing that other people don't have so they can show it off and flex on them, even if that thing isn't particularly good.
In summary:
>Buy a new laptop based on max specs for minimum outlay because you need to work away from the office? Not consoomer.
>Buy the latest MacBook Pro even though the one you already have is adequate for what you need so that everyone can see you have one at Starbucks? Consoomer.
>Buy some nice-looking, comfortable shoes for a specific purpose? Not consoomer.
>Buy the new Manolo Blahniks because OMG you HAVE to have them and then never wear them? Consoomer.
>Get a cat from a shelter because you want a furry, musical hot water bottle that never goes cold? Not consoomer.
>Get a fucking Caracal because Big Floppa memes are cool right now and everyone will be REALLY impressed that you have one? Consoomer.
>Go to see a film because it looks entertaining and the reviews say it's a good time? Not consoomer.
>Go to see the Ghostbusters reboot because you can post on Twitter that you saw it and seeing it means you Respect The Wahmens and it will own the Chuds, even though actually watching it is like attacking your genitals with a cheesegrater? Consoomer.
