That’s the situation that Expedia finds itself in these days. The world’s largest online travel agency recently posted another quarter of weak results as competition increased in the off-line brand marketing channel from Booking.com, TripAdvisor and its own Trivago. To the observer it seems that Expedia is finding it difficult to retain dominant market share in the US after rivals such as Priceline Com started aggressively advertising their brands, forcing Expedia to ramp up its own spending. For example, TripAdvisor – now spun-off from Expedia – is set to spend $30 million on TV advertising for its new hotel meta-search functionality. In terms of the US market, Hotwire was the most advertised online travel brand on US TV, according to Cowen and Company, spending $4.4 million. It was followed by Priceline.com on $3.9 million, then TripAdvisor on $3.6 million and Booking.com on $2.3 million. From a parent company perspective, Expedia is said to account for more than half of all current online travel brand TV advertising – some $12 million in total in June. That’s out of a likely total of $1.7 billion across all advertising channels in 2013, behind Priceline.com on $1.88 billion. Get the full story at Diginomica