Prompted by TV and advertising clients, Nielsen plans to launch its mobile ratings this fall. However, the company says that factoring mobile phones and tablets into TV measurement will roll out slowly based on relatively low adoption and the common practice of time-shifting. According to Nielsen, live TV viewing has remained constant over the last three years, while time-shifting has increased 30 percent — something to consider since most mobile viewing takes place outside of the same-day ratings window.

Cheryl Idell, EVP of U.S. media, walked reporters through the process during a panel this week of the Television Critics Association summer press tour. Although optimistic, she noted that traditional ratings would not experience an immediate lift.

“Around September through November there will be a preview period where the [mobile ratings] won’t be included in the [traditional] ratings,” said Idell, explaining that networks want a first look at the data.

“And even then, lifts will be marginal — at least where live-plus-same-day ratings are concerned,” according to The Hollywood Reporter. “The additional platforms will also only lump in linear ads (the one shared with first-runs on TV) and not dynamic ones (the targeted ads more common on vehicles like Hulu).”

Nielsen has yet to provide specific dates that its data will be made available to networks and when that information will be rolled into public ratings, but the company suggested public availability by year’s end.