For many clients, you may encounter that a corresponding blogosphere does not exist to get links from. Eg: A signboard maker. You won't find sites fully dedicated to signboards.
Yes, you can get links from blogs that talk about promoting your business, branding, etc but you will only get page-level relevance, not domain-level relevance.
What can you do in this case?
Well, a strategy I use is to guest post at sites of the same businesses in other cities. This works wonders because sign board makers in other cities are not competitors of your client hence do not hesitate in accepting your guest posts.
Mind you - most businesses don't know what a guest post is so you will have to position it as "collaboration"
- So just Search for - intitle:Business type + "other city" in google and scrape the results.
- Get a list of results for at least 10 cities and send them an outreach email.
This strategy never fails to work. I have scored hundreds of relevant links this way for clients where there is no passionate blogosphere in the niche.