Rising SEM costs may have killed this Aussie OTANewsBy Sean O'Neil | May 22, 2013Share This article was originally published on Say bye-bye to Check-in.com.au, a once popular Australian online travel agency (OTA), whose voluntary liquidation was announced on May 21.The agency claimed to have booked one million reservations since it was founded in 2002.As of this moment, the website is still up and running without any notice that it has stopped taking bookings. But an attempt to make a booking ended with the message that the "website is undergoing maintenance and not processing reservations."Australian news blog Travel Trends reports: The site has historically performed well in terms of traffic with [its owner] telling TravelTrends.biz in 2010 that it was attracting 450,000 unique visitors a month. However, at the time he said rising search engine marketing costs [SEM] had become a major challenge for the business. As result, Check-in.com.au increased commission to 15% to give it extra funds it needed to compete with the free-spending multi-national online travel agencies.Share this quote Comments on the original Travel Trends post suggest that many accommodation owners have struggled to receive timely payment from the OTA in recent months.The reasons behind any company's death are always complicated, but if the autopsy blames search engine marketing (SEM) -- or buying traffic through paid search listings -- other small online travel agencies who also face rising SEM costs may have cause to worry.