OpenCage Data infringing OSM license? is a website that offers a service where you can buy OSM data on a regular basis in a format of your choosing. Isn’t this a clear violation of the ODbl licence?

The ODbl license state:

Clearly OpenCage data “alters or build upon our data” and they distribute it as a paid service. They claim they are not selling the data, but selling the conversion service.
I’m not a layer, but I think this statements smells. If they are right and it is legal what they are doing, what is the value of the ODbl license anyway?

It’s fine to sell data from OSM, as long as those receiving it get the appropriate rights under the ODbL. In general, this will give recipients access to the underlying data (in the case of produced works) and also the right to give away the data for free (under the ODbL) to third parties if they want to. This last condition means that the seller runs the risk of only selling a single copy of the data, and then having the first buying collapse the market. (Though this is less of an issue when continual updates are being supplied.) The seller also has the problem that anyone could obtain the same data directly from OSM and compete with / undercut them.

Thus what buyers are getting from them, i.e. what they’re really paying for, is the conversion service. A good service, providing files in suitable formats with suitably filtered content, could well have a significant value to some people. There’s nothing really underhand in them doing this, unless the company is not up front about the fact that you could get the original OSM data for free without paying them, or they fail to adequately attribute OSM or inform customers of their rights under the ODbL.