One of the most common concerns we get as expired domain brokers is that often the topical trust flow of a domain is not representative of what the domain is supposed to be about. Expired domains or not, topical trust flow is an unreliable metric and doesn’t carry much weight. Here’s why.
Common Misbelief: The TTF of a domain must match the topic of the domain.

There are many people out there that buy expired domains and are highly concerned over the topical trust flow (TTF) of the domain. They think that the TTF of a domain must match the subject that the domain was about in the past.
For example… say we are selling a domain that was used for a dog grooming business. Many people that buy this expired domain think that the topical trust flow of the domain indicates what the domain was about, not what we see in archive.org. They think that if it were a dog grooming website then the TTF would be in “recreation / pets” as shown in the example below.

While the topical trust flow category sometimes aligns with the niche of the domain, most of the time it doesn’t.
Example: the topical trust flow of a carpet cleaning domain won’t necessarily be in the topical trust flow category of “carpet cleaning” or even “cleaning”. Carpet cleaners don’t link to each other so an expired carpet cleaning domain likely won’t have carpet cleaning backlinks and if it did that would just be unnatural. It would likely have links from directories or even from news sites in the form of press releases.
More realistic topical trust flow categories for a carpet cleaning domain would look like this:

The reason this carpet cleaning domain has topical trust flow categories irrelevant to carpet cleaning is because its backlinks are from a few different directories. The TTF categories of those directories are computers, business and shopping. That doesn’t even mean that they are computer, business or shopping directories. The TTF of a domain is a combination of the TTF of its backlinks…. and the TTF of those backlinks are a result of THEIR backlinks… and so on. So the TTF metric is as unreliable as the trust flow metric itself. You can see why I also think trust flow is unreliable in this article.
Let me go one step further and say that I don’t believe topical trust flow is relevant at all.
Here is the topical trust flow of target.com.

How many of you would be upset if your domain had a link from target.com? This domain has some serious push. Let’s just say that target linked to a carpet cleaning website for some reason or another. Let’s pretend that Target has a blog and that they linked to a cleaning site because they had an interview about how people could keep their house clean using Target products. That link would be completely natural, contextual, have some serious push, but it would throw the topical trust flow out of whack. It would make the TTF of your cleaning domain that of “business / retail trade” which is NOT cleaning. But that is okay because it’s a natural backlink.
Another example: Everyone would love to have a link from Huffington Post… no matter what niche. It is commonly agreed upon in the SEO industry that this would be a quality link to any site. People pay big money for these links. Any site could be linked to from Huffington Post in a story and it would be a natural link. But here is the topical trust flow of Huffington Post.

If you had a link from Huffington Post, likely the primary topical trust flow of your site would be in news / weblogs. If you have a pizza restaurant website with a backlink from Huffington Post then its primary topical trust flow would be in “news / weblogs” not “restaurants / pizza”. And that is okay, because in theory this would be a natural link too.
This may sound silly but many people we sell domains to are very concerned with the topical trust flow of the domain they are about to buy. If they buy a plumbing domain but the topical trust flow is not in plumbing specifically then they want a new domain when the domain is perfectly fine if not great. We don’t do exchanges for this reason but when people get so fixated on the topical trust flow of a domain then they miss out on a lot of great opportunities.
What to worry about instead of tropical trust flow
Instead of worrying about topical trust flow, or any metric for that matter such as trust flow, you need to look at the domain as whole and ask yourself “does a link from domain make sense?”
If you are buying expired domains from a broker then it’s hard to analyze the domain as a whole prior to purchase as you will likely only be given a handful of metrics. That’s why it’s important to buy from a reputable broker or even learn to scrape your own expired domains.
Most brokers are also not going to go through every domain on the sheet to find a domain with the topical trust flow category of your choice because it’s too time consuming and doesn’t really matter that much for the reasons listed above.
When you get an expired domain what you need to think about is “how can I link to my site in a natural way?” Ryan Stewart wrote a great blog post on what a a natural backlink profile looks like. I highly recommend the read.
The point I’m trying to make is that the topical trust flow of a domain is often inconsistent with what the domain is or was about, and regardless of topical trust flow, you can link from many different types of sites in a natural way if you use your head and get creative.
Example #1: Here is the topical trust flow of a site I worked on in the past. They are a guided hiking company. They have a link from a site with the TTF of gay, lesbian & bisexual. That is a 100% legitimate link, 100% relevant, and 100% natural and white-hat. Many people would freak out if they saw this in the TTF of one of their domains and not want the domain. This is simply unreasonable.

Example #2: I was doing some online baking with Chase today and they linked to Adobe to download a PDF viewer. Adobe is in the computer / technology niche and Chase has a primary TTF of business / finance, but it is linked to in a natural way. I highly doubt Adobe is being penalized by Google because they have a finance link. I also highly doubt that Adobe is sitting around for hours every day fretting that they are getting backlinks from things that don’t have computer TTF.

In conclusion…
You cannot make domain buying decisions off of tropical trust flow by itself. You shouldn’t make a buying decision off any one metric for that matter as I’m sure you know to some degree, but I won’t go into all of that in this blog post.
It always comes down to looking at the domain as a whole and asking yourself “Does this domain make sense?” and “can I link this in a natural way to my site?”