They're fundamentally B2C because the hardest part is getting the consumer virality engine running. Once the consumers are there, the B2B part (eg the ads engine) is relatively easy. I won't say trivial, but I would guess literally 2-3 orders of magnitude easier if you have a large and engaged audience. B2C success is the rate-limiting step.
> fundamentally B2C because the hardest part is getting the consumer virality engine running. Once the consumers are there, the B2B part (eg the ads engine) is relatively easy
Social media is neither. Ben Thompson's aggregator aside from the B2C/B dichotomy shines in this example. Snap and Twitter notoriously struggled with ad sales, for example.
Twitter was doing $5 bill pa of ad sales... Snap is doing over $4 bill pa. Twitter was sold for ~$40 bill, Snap is currently at $18 bill market cap.
That isn't notoriously struggling. The statement that the ad component is relatively easy is borne out by the facts. There are zero companies doing lots of ad revenue with very few users, and practically every service with hundreds of millions to billions of users spending their time looking at said service is doing significant ad revenue.
The only way one can think they struggled is if compared to the two wildly outlying, greatest ad revenue machines in the history of the world.
I think the struggle is people don't respond (convert) on those platforms for whatever reasons that are inherit to their audiences or the app itself. If users don't convert then businesses aren't going to spend on ads. I work in marketing and Twitter has always been hard to have any sort of positive return on. Big brands can afford that but the millions of smaller businesses can't.