Ad network RadiumOne is following Facebook’s example as it tries to figure out whether viewers liked an ad.

The San Francisco startup is launching a new feature called the “R1 Like Button,” which brings the “like” button that Facebook popularized into the world of advertising. If advertisers choose to include it, viewers will be able to both like and share an ad. When viewers like an ad, they’re giving RadiumOne data about what ads are relevant or interesting to them, and the network can hopefully deliver better-suited ads in the future.

The share option, meanwhile, allows viewers to share an ad on Facebook, Twitter, email, or elsewhere. After all, ads can include useful or at least entertaining content, so the share button creates an easy way to help them spread virally. And presumably, sharing provides another source of data about viewer preferences.

The idea of asking for user feedback on ads seems to be on the rise. Perhaps the most prominent example is video site Hulu, which asks, “Is this ad relevant to you?” during each commercial. But RadiumOne said it’s the first ad network to include this feature. And there are early signs that this is useful data, with shared ads seeing a 28 percent higher conversion rate (i.e., it’s 28 percent more likely that a viewer will actually click on the ad) than unshared ones. RadiumOne also said 32 percent of viewers who “liked” an ad visited the advertiser’s web page within five days.

RadiumOne is the re-branded version of gWallet, an offer startup that raised a $12.5 million round led by Adams Street Partners and Trinity Ventures.

You can watch a demo video of the like button here. For another example of how advertisers are creating new ways for viewers to interact and offer feedback on ads, you can also check out AdKeeper’s “keepable” ads.