Softer revenues from portal advertising and services led to a double-digit revenue decline for WebMD in the first half, while rival Everyday Health grew 35% when compared to the first six months of 2011.

WebMD’s revenue fell 19.6% to $219.6 million, from $273.0 million during the same year-ago period. Behind the dip was a second-quarter 23% drop in public portal advertising and sponsorship revenue, to $93.7 million compared to $121.1 million in the same quarter last year, and a 7% slide in private portal services revenue, to $18.9 million vs. $20.3 million in the prior-year period.

WebMD also lowered its expectations for sales commitments and revenue for the balance of 2012. “The company anticipates that many of its customers will continue to reevaluate expenditures in various areas, including marketing expenditures,” it said in a statement.

WebMD’s new CEO, ex-Pfizer exec Cavan Redmond, came on  in June. His predecessor, Wayne Gattinella, left in February amid flagging ad sales and an aborted plan to sell the company.

The firm continued to chalk up advertisers’ apprehension to the “impact of patent expirations across their businesses as well as greater than expected delays in new product launches.”

Traffic to the WebMD Health Network during the second quarter grew, reaching an average of 106.9 million unique users per month and 2.5 billion page views for the quarter, increases of 29% and 25%, respectively, from the prior year period.

Everyday Health reported that advertising and sponsorship from healthcare companies grew 35% when compared to the first six months of 2011. The privately held firm said revenue from its top 20 advertisers grew 31% for the first half of 2012, compared to the same period in 2011.

The firm has undergone rapid changes, including the December launch of a video channel on YouTube, last September’s TV series debut and the August 2011 hiring of SVP/GM Paul Slavin.

The company has 25 digital health and life properties in the US and is increasing is global reach—it announced in July that it was breaking into the UK with its first site, WhattoExpect.co.uk, in November and plans to launch EverydayHealth.co.uk in 2013.