Are you or someone you know into the travel organizer business? Build a blog. The digital realm is becoming the go-to place for trip planning. Dedicate the blog to European travel only. And you can eventually build more blogs and target different geos.
This niche is expansive as you will be focussing on the whole of Europe as a destination. Europe is an ever-popular continent for travelers from around the world, signifying a high demand for European travel-related content.
This blog idea would be ideal for travel agents dealing in/with expertise in European destinations, and ideally with extensive knowledge of the continent. You can even be a local looking for the opportunity to share your insights. Suggest travel itineraries for different European countries/cities, tips for budget travelers, luxurious European experiences, and tips about the culture etc.
You may want to monetize the blog by doing affiliate partnerships with booking; collaborations with travel companies, hotels, and airlines, etc. Ad revenue is of course always an option. The blog can act as a lead generator in any case.
Blog Name Idea: TravelAgentsEurope.com