The two charts below show that the overall number of page views at the top airline websites as well as the top online travel agencies has moved down over the last 12 months.
At the same time the dollars transacted online has increased. My immediate conclusion is that consumers are growing more comfortable with shopping for travel online and are visiting fewer sites than in the past when making their purchase decision.
Southwest, Delta & American

Expedia, Travelocity & Orbitz

Source: Alexa