Out-of-home advertising, from billboards to skywriting, has a lot going for it, and right up there is cachet.

A good out-of-home component can be that last dash of smarts that sets off a media plan in the eyes of a client. Most media folks will go out of their way to include some such element in their planning.

But they have one big problem with out of home overall, and it's one they've had for a long time: a lack of reliable means to track and document effectiveness.

A clever campaign might get lots of buzz but just how many people were actually exposed to it too often remains a mystery. And these days, with ad dollars tight, buzz alone isn't enough.

While buyers applaud some of the advances in measurement, such as the new Eyes On tool being rolled out by the Traffic Audit Bureau, which aims to project who actually sees an out-of-home venue, they believe a lot more needs to be done.

That's the outcome of a recent Media Life survey of media planners and buyers.

Asked to name the biggest issue in out-of-home media, the largest share, 54 percent, agreed with this statement: "Measurement -- we need better ways to tell who's seeing these messages."

That topped creative issues at 23 percent.

Further, some 69 percent cited measurement issues as the leading negative in considering inclusion of an alternative media element in a media plan, with a lack of research a distant No. 2 at 42 percent.

Some 80 percent said they wanted to see more coverage of measurement issues in Media Life.

Asked to comment on measurement issues and what changes they'd like to see, media folks boiled it down to "believable, verifiable numbers," as one respondent put it.

Wrote another: "Universally transactionable ratings would be nice."

And yet another: "Eyes On is surely a move in the right direction. Additional improvements that help media planners and clients understand the measurement and effectiveness of OOH would be wonderful."