The Snapchat service has proven to be a boon to certain brands, mainly due to its effective reach to millions of users on a daily basis. However, if these brands aren’t considerate over what kind of ads they put together, they could find themselves in danger of being skipped over.

Digiday reports that a lot of users tend to move on quickly from ads that don’t keep their attention. Although this isn’t the same for all brands across the board — no one else has reported on the site’s advertising trends — but the site does run 10-second ads with the ability to skip over them, indicating that making them ‘skippable’ makes them an important factor when it comes to sales.

As you can see from the chart below, there are four different examples as to when users watched ads. Each time, it appears that the percentage of viewers watching said ads after a certain number of seconds drops almost instantly, in just a matter of two seconds or more. Only around 10 percent seem to watch the ad in its entirety.

“Completion rates for Snapchat vary depending on the creativity of the ad,” said an anonymous partner with Snapchat. “Most brands that try to be native, organic to the platform, have higher completion rates.

Some brands, as a result, are looking for more favorable viewability standards from the company. They haven’t answered, though, as the advertising model, charging for ones that even run for less than a second, remains in place.

Snapchat is aware of such concerns, according to Digiday. “It’s early days,” Snapchat said in an email. “We are very focused on continuing to drive value for advertisers.”

Even with the small amount of time spent with video ads, the platform can still be quite effective.