1. Is already conditioned to buy marketing plans OVER THE PHONE. In 10 years I don't remember a single sale being made face to face. This means you can be anywhere and market your services to anyone.
2. Already has large marketing budgets set aside. Most of the companies in this niche are paying at least $1,000 per month, up to $10,000 per month. They need to spend this money in order to compete with other Big Dogs in their niche.
3. A very small portion of the companies in the niche (maybe only 1%?) have a custom Facebook page, and even less are using any kind of sales funnel or any email marketing. Other marketing agencies that cater to this niche are still just doing SEO and PPC campaigns.
4. These folks are loyal too. My average client pays me $1500 per month and stays with me for 2+ years. They really appreciate what you can do for them.
Being a warrior since 2007 I have yet to see anybody talk about or mention this niche. Seems like most people are focused on the obvious dr, dentist, professional trade niches. While these are ok, they don't stand up to the money I can pull out of the Travel industry.
By travel industry, I mean hotels, inns, cabin/condo rentals, adventure travel, etc... Every small town has at least 1 hotel, while smaller cities can have hundreds of lodging options. This can be said for just about any town or city in any country in the world, which is why I don't mind sharing my info.
Because there are so many travel companies throughout the world, there are also quite a few internet marketing firms that cater to this market. I worked for one of the larger firms when it first opened, and in 5 years we had 70 employees and 8 figures in revenue per year.
If you were doing this by yourself with no employees (or outsourcing), the average person can handle up to 20 clients at about $1,000 per month.
There is so much I can talk about regarding this market, but it would require me writing a book, so if you have questions, ask away!