Right but on contribution side it basically taking unpaid labour then selling it to their paid customers. That part I have problem with. And you don't need ope

Right but on contribution side it basically taking unpaid labour then selling it to their paid customers. That part I have problem with. And you don't need open source model if you just want to give smaller might-be-a-customer a free, limited version. I guess it depends on what exactly is behind the paywall. Some have very weird limits, like Mattermost where you can use Gitlab for authorization in open core but for LDAP you need enterprise. We actually paid for it and were pretty happy with it but at some point they decided to double the price under excuse "but we added features"(that we did not use) to that version. So one Rails dev added a dummy "gitlab" oauth page for auth that's connected to our LDAP and we just switched to open core version... ...aand since then they doubled the price again. So suffice to say I'm a bit soured on open core model, when they tried to upsell us to more than we pay for O365 account for same features. I'm not saying it's all bad, for example VictoriaMetrics looks like it have very reasonable model (although lack of pricing on their page is... annoying), but it is model ripe for abuse, especially if company gets bought.