Well, since people is trying to interact with this information, I'd use as an advantage, as mentioned by Mattynabib, it really makes sense.

However, if for some reason you prefer not to, the answer would be to make this snippets of information an homogeneous message. The way it is now, it looks like a mix of marketing and interactive element (hence the clicks) . So what you need is to keep the marketing side and get rid of this perceived affordance. And in order to do it, simply join the information snippets in a sentence, like

6 books listed, 12 succesful listings and 2 active users

Note: I'm not sure if you really want to use this as a marketing copy. If so, I'd look for something better. Also, why "succesful listings"? Are there unsuccessful ones? If so, why to do an implicit mention to that negative aspect?

They should be clickable if users can interact with those things.

If you are displaying something that summarizes content that is relevant to users, it should be clickable to reach the underlying content.

Presumably on a textbook exchange website, users should be able to view the books that are listed. So let them click on "6 books listed" to get to that view.

Are "successful listings" relevant to users of the site? If so, again, let them click on that to view all the successful listings.

The same goes for "users". Can users view the list of users? If so, let them click on it.

If users can't interact with what you are counting, why show it?

For example, if "successful listings" are not something users can interact with, then what is the purpose of telling them how many there are? It creates the expectation that they can view and interact with them.

Perhaps you just want to impress users with the amount of usage of your site. If so, make sure the information looks like a promotion and not meaningful data. e.g.:

CHTB: the second largest book exchange on the internet, used by 1234 users to post 5678 books (and counting!).

Position matters

The subconscious factor making your test subjects want to tap those text objects is positioning. They are very much like the tabbed navigation solution that has become so popular on mobile (and now elsewhere).

It’s hard to retrain users

Despite your efforts to downplay them, the position appeals to users who want to explore the different views:

I wonder what books are already listed?

What is a "successful" listing?

Do I know the users that are active here?

Work with known patterns

1. Make the text objects look less like navigational tab controls. Positioning them away from the lower edge of the "card" will help. Reformatting them into a single block will also reinforce their meaning.

2. Your design feels unnecessarily divided. Is there any reason not to place the search field in the main header?

3. Make search look more like search.

Iterate based on test findings

As others have mentioned, users want those things to be navigation. My imagined questions above are hinting at reasons users may want to navigate to the data behind those things.

You don't have to answer every user desire, but when you start to see a pattern you may have stumbled onto something valuable.

It's a matter of relative 'clickiness' as well. Make the unclickable items less clickable by making the rest more clickable. The phrase here is: 'affordance'.

• the position of the three not-clickable items is very prominent: in your design, it's in the center of the page and it intregrates with the logo and the pay-off. That gives them a strong click-affordance.
• graying out hasn't helped you. In this design, it's easily understood as simply a stylistic choice to make this text gray.
• Your 'search' input is maybe not clear enough. Try to make this look more like search-input:add a border, a search-glass and a submit button (for example).
• You might also switch the position of the search bar and the 'unclickable statistics' and make the search bar part of the logo --> mimicking the Google default page.

The grey text actually makes them look more clickable as they stand out from the rest of the header. I would change them to the same color as the rest of the text (black).

Also, instead of "6 books Listed", I would use "Books Listed: 6". The colon subtly implies, "here's info" rather than "I'm a link".

Since the numbers "6 books listed" "12 successful things" .. are more like highlights.

I would try one of these to make it look like highlight or dashboard sort of numbers:

Increase the font - it makes it pretty obvious that its a heading of sorts. Have a panel for each item, in this case 3 panels. When I say panel it means having a light background and padding to the text.

Some thing like I tried above, but you can always play around with colors and fonts that suits your design.

You want to make the numbers bigger, change the font/color to differentiate them, and put them on top of the information they are describing. For example, check out the layout of a certain very popular site (look at the bottom right of this image). This makes the numbers look more like meters/indicators rather than links.

Theoretically you could make the text look a bit more "graphic" in nature, something more like a sort of hype-decoration on that panel; otherwise, I think graying it out is about as far as you can go - once they try clicking and it doesn't work, they'll probably stop.

But if you've tested this and people are consistently clicking there, you may want to consider finding out what they expect to happen when they click in those spots, and then consider MAKING them clickable... you could be missing an opportunity.

using inset text shadow gives the appearance of something set in stone: (with and without)

It's because:

1. (probably hard to change) The content begs the question "which?" so people follow their urge to find out.
2. (probably easy to change) They are in a body type font that suggests possible link material. Choose a presentational form - maybe sans-serif, maybe with thin caps, maybe with different weights and/or sizes between digits and letters etc.

It may be worth changing location in the page.

If these are user-specific stats, move them to the top-right box or remove them completely from the main page and put them in the user's profile.

If they are site stats, I'd bring them closer together, darken the text, and possibly change the font of the digits. A more 'digital' looking monospace font might indicate that they are information and not links.

That being said, I am one of those people that would look at those stats regardless of where they are or how they look and try clicking on them. Like others have said, if you have the data and feel the need to display it to the user, why not actually do so?