Apple’s iAds advertising program finally came to the iPad early this month, but it seems a bit late to the party. Mobile ad network Greystripe just announced that it has served more than 100 iPad ad campaigns in the last nine months.

So how are those iPad ads actually doing? Greystripe says they’re outperforming the advertising it runs in iPhone and Android apps as well as on mobile websites. 20 percent of the users who see the iPad ads choose to engage with the pictures or the videos. And those campaigns are delivering an impressive 60 seconds of engagement time on average.

As for the kinds of ads that are working, Greystripe says that video ads are more popular than images — not a surprise, perhaps, but the difference is bigger than it is on other mobile devices. (This seems like good news for other iPad ad companies focused on video, such as mDialog.)

Meanwhile, iAds, as previously mentioned, are only now coming to the iPad, months after the program initially launched. The program has drawn mixed reviews, with early participants impressed with the quality of the ads but complaining they take too long to create and that the campaigns are over-managed by Apple. And it looks like Apple has been adjusting the program, reportedly cutting the minimum ad buy from $1 million to $500,000.

Greystripe has raised $17.6 million in four rounds of funding, most recently $2 million from Peacock Equity.

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