They don't, not directly. That's why they've generally been winding down DGX Cloud. However, lots of folks dramatically underestimate their frontier models (Nemotron family), and they license those models (free) for embedding in MANY other, large tech companies' own products and platforms, which either directly or indirectly consume massive quantities of GPU time.

Nvidia is best known for selling huge volumes of GPUs to the hyperscalers & neoclouds, but I don't think lots of folks appreciate how many GPUs ISVs like Snowflake, Databricks, Teradata, etc consume, too, just by virtue of designing much of their internal products around CUDA & Nemotron.