Here are some organic and cost-effective ways to acquire your first 100 customers for a global task marketplace:

Reach out to expat and international communities on forums, Facebook groups, Reddit, etc. and introduce your service. Offer a special introductory discount.

Create a basic website and optimize it for search engines using relevant keywords. Write helpful guides and how-to articles to attract organic search traffic.

Start a blog on your site sharing real user stories, lessons learned, location guides, etc. Embed links back to your service pages.

Leverage social proof by asking early users for testimonials and case studies. Feature these prominently on your site and in your marketing materials.

Build partnerships with travel bloggers, influencers, and websites focused on global nomads. Offer them exclusive discounts to promote in their communities.

Run limited-time promotional campaigns via social media, asking people to share for a chance to win a free service.

Create Facebook ads targeting people interested in traveling, living abroad, remote work, etc. Start small and optimize continually.

Attend local meetups and networking events frequented by expats, digital nomads, and remote workers. Give a short pitch about your solution.

Reach out to universities and colleges with study abroad programs for partnerships and promotions.

Offer additional services like currency exchange, shipping, local guides to increase perceived value, and organic referrals.

The key is leveraging relevant communities through quality, engaging content, and strategic partnerships. Optimizing for word-of-mouth is very powerful for a new marketplace.