According to data provided by S&P Global Market Intelligence, the "Bloomberg platform for medical professionals," Doximity (DOCS 33.69%), saw its shares spike 34% as of 11:20 a.m. ET Friday.

The healthcare upstart rocketed past analysts' expectations on both the top and bottom lines and guided for a rosier upcoming quarter than anticipated.

However, a few nuggets hidden in Doximity's earnings call may be the real reason for the market's exuberant reaction today.

Doximity's investment thesis looks better than ever

Doximity counts roughly 80% of physicians and 60% of nurses in the United States as members of its platform. Providing a tailored, healthcare-focused newsfeed, the ability to network with peers, and a suite of workflow and productivity solutions, the company has quickly become a must-have for medical professionals.

Thanks to this adoption among the medical professional community, Doximity's platform is an attractive marketing space for pharmaceutical companies and hospital systems that want to reach physicians with their products.

Doximity's third-quarter results showed that this investment thesis continues to gain steam as it delivered sales growth of 25% -- its highest mark since 2022 and more than three times faster than the industrywide growth rate.

Best yet, this growth isn't just coming from new customers. The revenue retention rate among Doximity's top 20 customers was 122%, meaning that Doximity's existing customers increased their spending by 22% compared to last year -- even after accounting for customers lost to churn.

Simply put, the best and brightest minds at the behemoth pharmaceutical and hospital firms acknowledge the oustize return on investment provided by advertising with Doximity and continue to flock to its offerings. With the pharmaceutical industry still only spending one-third of its budget on digital ads -- compared to a 70% digital spend in most other industries -- Doximity still has ample growth ahead.