Education companies may find themselves unable to persuade districts to buy the professional development that goes with their products, often because school officials are turning to providing that training in-house.

Those decisions have consequences for vendors beyond smaller profit margins. If teachers and other staff don’t get high-quality training on new tools, systems, and platforms, those products aren’t likely to deliver results—and the districts using them aren’t likely to become repeat customers.

One strategy companies are using to set their professional development apart is “personalizing” that training …