Dropbox is one of the startup darlings of Silicon Valley, an impressive company with beautiful software. But that doesn’t change the fact that Google Drive is politely handing it its ass on a number of fronts since launching just three months ago.

Four randomly selected startups I have spoken to over the last couple of days have emphasized the impressive acceleration and impact that Google’s storage and collaboration software has achieved.

Freshly minted project collaboration software company Siasto has seen Google Drive take off since it integrated the service into its product. “We’ve seen a threefold increase in synching with cloud products – namely, Google Drive – since our integration with Google Drive,” says Siasto co-founder and CEO Niccolo Pantucci.

Instead of using Siasto’s native file-sharing features or “anything else” (which can only mean Dropbox), customers are turning to Google Drive, says Pantucci. “Since Siasto has gone fully Google, our Google Drive integration has seen pickup triple. The number of companies that synch up their Google Drive on the first day of using Siasto is astounding.”

Attachments.me co-founder and CEO Jesse Miller says that since the company added Google’s service on June 12, it has consistently seen 50 percent more Drive accounts added per day than Dropbox.

“Within one week of launching our Drive integration, there were already 20 percent as many Drive accounts authorized as Dropbox,” Miller says. He is quick to point out, however, that the numbers could be skewed, because Attachments.me is a Gmail extension and is primarily distributed via the Chrome Web Store.

For another startup, RightSignature, integration with Drive came at the behest of its users. The integration has produced clear results. So far, five times as many RightSignature users have activated Dropbox integration compared to Drive. But the Dropbox integration has been available for 22 months, compared to just 2.5 months for Drive. “More telling,” says CEO Daryl Bernstein, “[is that] currently every week RightSignature users are activating the Google Drive integration at a 40 percent greater rate in comparison to the Dropbox integration.”

Meanwhile, Lucidchart, whose Drive results were highlighted at the recent Google I/O event, has not yet integrated with Dropbox because it doesn’t offer the ability to draw diagrams, as Google does. “We’re confident that Drive provides a more engaging experience for users, because it’s not just about storage with Drive, it’s about centralizing all of your Web apps and Web life into one place,” says Dave Grow, the company’s vice president for strategy and operations. Ultimately, to compete with Drive, Dropbox and others may have to consider moving beyond just storage and more into line with a platform-based product that plays host to third-party apps.

We should be careful not to draw too strong a conclusion from such a small sample. It is early days for both Google Drive and Dropbox. But the findings from these companies at least add credence to the idea that Drive is a serious contender and perhaps enemy No. 1 for Dropbox. The power of the Google brand and reach will be difficult for Dropbox to overcome, especially outside of the techy circles in which it finds most favor.

For now, however, Dropbox still has the numbers advantage. It claims 50 million users, while Google Drive has 10 million. Let’s check back in six months.