How can I advertise a travel website?

Optimize your site off-page. Of course, post your services to free classified sites to have traffic to your site.

Like any other website, use:
- Free Directories Submissions
- Social Bookmarking Websites
- "Dofollow" Forums
- Link Exchange with relevant travel websites

Hi.
You can do link exchange with relevant and high PR Travel related websites. Take a part in forums discussion with your website link in Signature.

There are specialist niche travel sites where you can add your site and get fast exposure. I've added bookmarks there recently and they've achieved high ranking very quickly. There is a very strict anti-spam policy so tread gently and add accurate details and relevant tags etc. Also definitely worth posting to delicious, digg etc. All can get good results.

Try marketing it through blogs and forums. You can also start sending emails, ebanners and emailers to the set of email ids which you can have from various agencies who give email ids based on demographic or geographic details on a very minimal price.

Try tieing up with people whose business compliment your business.

You can do some directory submission, forum posting, blog commenting, blog posting, article submission, press release submission, social bookmarking..

You can also try joining and be active in travel forums. This may help increase the number of your real visitors or potential customers.

You can write some articles about place that tourist attractions and add your site in it,go to forums that consumer ask about the relative question.

You could start a blog writing about the various holiday/packages/tours that your site offers. This is a low cost method if you do the work yourself. Alternatively article promotion is another good technique.