LONDON/WASHINGTON: Online advertising has now been accorded a "walk on water" status by much of the advertising industry, but the effectiveness of the medium and the return on investment it provides have yet to be proved, according to WARC Online's regular columnist, Tummler.

Many marketers and brand owners were suspicious of using the web as an advertising tool in the immediate aftermath of the dotcom crisis at the start of this decade.

However, Tummler argues the medium has now "emerged from its geeky chrysalis to become adland's most fashionable butterfly."

To this extent, media and advertising luminaries from Steve Ballmer, ceo of Microsoft, to Sir Martin Sorrell, his counterpart at WPP Group, have long been encouraging the shift to digital media.

Marketers, however, should be "conscious not only of the pitfalls of following other people's money," as many investors recently learned having placed their money in the hands of Bernard Madoff, Tummler says.

Similarly, there is a need to pay attention to "increasingly vocal debate as to the reliability of online's ROI measurement methodology," rather than unquestioningly expecting a strong return.

To access Tummler's latest fortnightly column in full, please click here.

Data sourced from WARC