Websites and nightclubs would've been perhaps less conceivable, but still conceivable, dating businesses at many points in human history. Paying a mediator to gather theoretically young and/or marriageable and/or lonely people together, virtually or in-person, is fathomable by the lower-functioning, even if the demand for such a service is recognized by them as indicative of social decay. Once known mediators (family members or close friends) are removed, and the customer becomes the individual directly seeking an introduction on her or his own behalf by utilizing the services of an unknown mediator (silent partner in a nightclub business), the relevant taint becomes an obvious prediction that an ordinary person can be walked through well enough to understand, like infanticide for eugenic or convenience purposes. The concurrent limitations of effectiveness and/or necessarily associated social characteristics, can be understood by many more.
At the individual level, the individual is truly paying for access to others. The individual consumer, to the extent the business model is effective, isn't actually interested in the cover charge, the room(s), the overpriced drink(s), the chance to develop a paid online profile, et cetera, but only the potential social gains from such an investment. The other people are the product that the consumer seeks, even though they have not been bred, fed, housed, grown, and polished up by the website/nightclub, ergo things we all are bored of hearing about already, like ladies night or randomly generated female/twink/sub profiles that attempt to elicit investments.
We're here not to delve further into these brilliantly evil business models, nor to decry very much the world that makes them work, but to note the existences of such models: models where the economy ceases to have any relationship to production, but merely represents a form of scavenging upon despair. A lottery ticket or pornography purchase is a more legitimate transaction than a nightclub admission or website membership, because each of the former pair represent a purchase of something, even an infinitesimal or rigged or illusory something, which has been produced; the website or nightclub, by contrast, is more like a business purchasing lists of contact information for potential customers from a data consolidator, except that the hope is not economic profit but products which are typically not considered products, such as socializing. The person searching clubs and/or websites for potential mates is an interesting example of inverse consumarketing.
This, though, remains beside the point. We consider the sale of externally-generated products--human products which are not slaves or acknowledged as products--because political memes are political cartoons, albeit ones created by unpaid private individuals who are happy to receive recognition in exchange for enriching others. Social networks are a more evolved form of dating websites, which are a more evolved form of nightclubs, which are a more evolved form of bride brokers (not modern ones aimed at selling foreign women into wealthier polities, but ones that used to help the children of more atomized bourgeois families obtain suitable matches). Now, on a social network, the product is the consolidated obvious insights of other people, recited for presentation so that others will come and generate advertisement revenue not because that place is itself worthwhile, but because other people are there. It is a summer night light for a group of moths, generating revenue with incredible efficiency, in the sense that the majority of content--eventually all content--does not need to be produced by the rentier. Mass media entertainment was able to eliminate and efficiencize the requirement of creating narratives with formulaically determining them, then to secretly pillaging older products (plagiarizing), then to openly pillaging older products (buying rights and remaking with updated mores and/or technology), then to saving even more capital, somatizing Terra further, by promoting associations of contract workers, the vast majority of whom can be wholly disregarded. Eventually, merely branding associations whereby externally-generated content is traded. No longer does the parasitic merchant need to, as in "the Dark Ages," engage slaver-pirates of land and sea to isolate fortified settlements in order to gain value by exclusively shifting letters of credit and varying goods between them; now, the merchant need only be a rentier of illusionary commons, charging target audiences for the privilege of evaluating, and being evaluated by, others.