• by David Goetzl  @dgoetzl, May 6, 2009

Constant Contact is expected to provide an update on how its 8-month-old radio campaign for the email service provider is performing when it releases first-quarter results Thursday. Spots have run on the ESPN radio network and on stations owned by CBS.

Management has suggested the campaign, targeting small businesses, is helping grab new customers, which it said grew 54% in 2008 to 253,400. Revenues for the October-December period, the first full quarter when the campaign was on air, were $25.5 million, a 61% year-over-year increase.

Still, CEO Gail Goodman said in a February earnings call: "It's worth noting that our evaluation of radio when done completely, really needs more time than we've had to date. So our full evaluation of our spend won't happen until we can look back and do statistical analysis."

More details on ROI could come on the earnings call Thursday. Constant Contact is believed to be the first and only ESP to run a campaign in a non business-to-business medium.

Goodman has said the budget calls for the radio campaign to continue for the full year. The company did not specify the cost of the media spend, but said sales and marketing expenses were $13.1 million (52% of revenue) in the fourth quarter of 2008.

A current spot promises businesses to "help ... generate the almighty referrals" and plugs a trial offer.

The company says the campaign is running on "five major [radio] networks," meaning, there are three others in addition to ESPN and CBS. It did not identify any in an earnings call.

Constant Contact's stock was trading in the $16 range Wednesday, down from a 52-week high of $21.24, but up from a low of $10.32.