NEW YORK: The US advertising market rose only slightly in the first quarter of the year but when the impact of last year's Winter Olympics is stripped out a much brighter picture emerges, new data has shown.

Figures from Standard Media Index (SMI), the advertising data group which captures 80% of the total national ad spend from global agencies, showed that the overall market was 1% up in Q1 2015 compared to the same period a year earlier.

And when it excluded the effects of the Sochi Winter Olympic Games, held in February 2014, SMI said that Q1 TV revenues showed "solid growth" in both broadcast (+7%) and cable (+4%).

In particular, advertisers had boosted their spending in the scatter market across both broadcast (+13%) and cable (+9%), with the overall scatter market up 11%.

"A nice uptick in scatter dollars fuelled national TV growth in March, which is certainly a good sign for the health of the ad marketplace," said Scott Grunther, SMI's executive vice president of media.

"The solid growth figures when you remove the impact of the winter games from last year provides reason for networks to be more optimistic heading into upfront season," he added.

SMI's data also showed that, in addition to TV, digital had contributed significantly to the growth of the overall ad market, registering a 23% increase for the quarter in Q1; digital's market share of total ad dollars also jumped five points.

This increase had been driven mostly by ad networks and ad exchanges which rose 39% in Q1, alongside large increases in social networking sites (+41%) and pure play video sites, such as YouTube.com and Hulu.com (+38%).

Automotive, the largest advertising category, remained soft, down -3% for the quarter, while consumer electronics and business services and recruitment both jumped +17% to emerge as the fastest growing categories.

In other media, ad spend on magazines declined by -7% and on newspapers by -2%. Radio was also on the losing end with advertisers dropping off by -1%, but there was better news for out of home as ad revenues rose by +1% in Q1.

Warc's Consensus Ad Forecast, based on a weighted average of predictions from various sources including advertising agencies, media companies and industry bodies, expects growth in US adspend of 3.5% this year, with a further rise of 6.0% forecast next year.

Digital is seen to be the key driver this year, with 15.4% growth, while TV adspend is expected to record milder growth of just 0.7%.

Data sourced from SMI; additional content by Warc staff