[nemothekid]

Lets skip the fact that a your average 17yo may not even have a credit card to begin with.

If Snap were to start charging tomorrow, what would their value ad / sales pitch be?

The original reason people used Snap was ephemeral communication with their friends. Snap can't "sell" that. If I buy the Snap App, and my friends aren't there then the app is useless to me. The smaller the network is, the less valuable it is to me - and if I do buy in, it then becomes my job to also convince my friends that Snap is worth is paying for. If one of my friends does not renew their subscription, the value of the service to me also declines. I don't think any social network can be viable by subscription - the most valuable part of a social network is the network, and the under a subscription fee, "Snap" would always have to choose between making the network for valuable and generating revenue.

Thats why the ad model works so well for social networks. The more people you have, the more attractive it is to consumers as well as advertisers. This is different from something like a news publisher - the amount of people also reading from that same publisher doesn't affect my enjoyment of their content.