[nijave]

>There's nothing special about having software where anyone can contribute freely, that makes it attractive to customers

Community, support, acquisition, extendability and code quality.

Community/Support -- lots of documentation available for free, generally multiple vendors that offer paid support, free access to updates. Don't have any data but I suspect finding people to support/run it is easier (skills are more marketable and easier to learn on your own)

Acquisition -- eg less of a vetting/auditing process for places where that matters (you can handle vetting the code and supporting company separately)

Extendability -- you can hire developers to add features or integrate without being subject to the owner's timeline e.g. you don't have to plead for features

Code quality -- being open, it's more apparent if the software has a high number of bugs or large amount of technical debt that could lead to instability. Usually the issue trackers for OSS are open to everyone

These apply more to large companies with dedicated teams

[altdataseller]

3 of those 4 still apply to Elasticsearch. Mongo, another example has the same license and loads of docs freely available. You can still hire devs to add any missing features to Mongo (albeit you will have to fork it). You can still view their issues in GitHub too