Author Matthew Barker of this article at tnooz finds travel marketing frustrating.

Key sources of frustration:

• High acquisition cost
• Long sales cycle
• Low purchase frequency, little repeat business

Recommended strategies/tactics to overcome:

• Early in the sales cycle, deliver value.
• Use downloadable assets and other good content to capture audiences.
• Paid channels are cheaper near the top of the funnel.
• Don't go for the close prematurely.
• Be consistent across channels.

Solid article, and a lot of solid comments that you should read also.