Link building is a crucial aspect of search engine optimization (SEO), and various industries leverage it to improve their online visibility and rankings. Here are 20 industries where link building is commonly employed:

1. Digital Marketing Agencies: These agencies often engage in link building to enhance the online presence of their clients.
2. E-commerce: Online retailers use link building to drive traffic to their websites and improve their search engine rankings.
3. Healthcare: Medical professionals and healthcare providers use link building to establish authority and credibility online.
4. Finance: Financial institutions and professionals employ link building to enhance their visibility in search engine results.
5. Real Estate: Real estate agents and companies use link building to attract potential buyers and sellers to their websites.
6. Travel and Hospitality: Hotels, travel agencies, and tourism-related businesses use link building to increase their online visibility.
7. Technology: Technology companies use link building to establish themselves as authorities in their respective niches.
8. Education: Educational institutions and online learning platforms leverage link building to attract students and improve their rankings.
9. Legal Services: Law firms and legal professionals use link building to enhance their online reputation and attract clients.
10. Food and Beverage: Restaurants, food blogs, and culinary websites use link building to drive traffic and improve their online presence.
11. Home Improvement: Businesses in the home improvement and renovation sector use link building to attract homeowners and increase their online visibility.
12. Fitness and Wellness: Fitness centers, wellness coaches, and health-related websites use link building to reach a wider audience.
13. Automotive: Car dealerships, auto repair shops, and automotive blogs engage in link building to improve their online visibility.
14. Fashion and Beauty: Fashion brands, beauty influencers, and retail outlets use link building to drive traffic and improve their search rankings.
15. Entertainment: Media outlets, entertainment websites, and streaming services employ link building to attract users and improve visibility.
16. Nonprofit Organizations: Nonprofits use link building to increase awareness, attract donors, and promote their causes.
17. Event Management: Event planners and organizers use link building to promote events and attract attendees.
18. Home Services: Businesses offering services like plumbing, electricians, and pest control use link building to enhance their local online presence.
19. Pet Care: Pet-related businesses, including pet stores and veterinary services, use link building to attract pet owners.
20. Government Agencies: Government organizations use link building to disseminate information and improve their online presence.

In addition, casino and gambling sites use guest posting as an effective way to drive traffic.

Regardless of the industry, the key is to focus on building high-quality, relevant links from authoritative websites to improve search engine rankings and drive targeted traffic.