Google last week started placing a "searcher beware" warning label on mobile listings with an irrelevant redirect, a move that could see brands? mobile clicks drop by as much as 60 percent.

Mobile searches for a specific item that produces listings with a direct link to that item on desktop but redirecting smartphone users to a home page will come with the warning "May open the site's homepage" and a link labeled "Try anyway." For brands with dedicated m.dot sites ? which includes a significant portion of leading retailers ? this is the latest penalty from Google for mobile search engine optimization that does not provide a good experience for smartphone users.

?Pages that have this warning attached to it are going to see a decrease in click through of at least 30 percent and maybe up to 60 percent,? said Brian Klais, CEO/founder of Pure Oxygen Labs, Madison, WI . ?By forcing mobile users to have to make the decision, it is going to decrease click traffic because anytime you introduce friction, make them think, it forces them to keep looking.

?This is a significant issue on retail sites, because the majority have this issue happening,? he said.

?Google wants searchers to understand that brands don?t have their act together. Google is extremely sensitive to searchers? user experience.?

Getting serious about mobile
The new warning is already appearing on some brands? sites.

For example, smartphone users who search for the BMW 320i will see the BMW site as the top listing. However, since the deep link on BMW?s desktop site for this car redirects smartphone users to the mobile homepage, the listing includes the disclaimer.

The warning could force some users to not click and move on to the other listings.

It was just about a year ago when Google first warned marketers that it would be penalizing them for inferior mobile search experiences with lower ranking and page de-indexation for poor practices such as too many error pages.

The new penalty is the latest indication that Google is taking mobile search seriously and it wants marketers to do the same.

Creating a good mobile search experience is imperative for Google, whose share of mobile search is taking a hit as consumers increasingly conduct searches within apps.

Be proactive
According to research conducted by Pure Oxygen Labs late last year, 67 percent of top retailer mobile sites have this problem of faulty/irrelevant mobile redirects. As a result, they will likely be affected by Google?s move.

The new warning is a significant development for brands because it is a new kind of penalty that they have not had to deal with before. The challenge for many marketers will be determining how many pages have this problem.

Google has said it will notify marketers in Webmaster Tools that there is a problem but is not clear if brands will be given an opportunity to correct the redirects before the warning appears.

However, Mr. Klais suggests marketer be more proactive about the situation.

?You can?t sit back and wait for Google to tell you have a problem because you could have a significant problem," Mr. Klais said.

?Google started issuing warnings about for a year and rolling out algorithm changes to penalize brands that don?t get redirects on mobile together,? he said. ?This is not new but they are finally putting some teething to it.

?Brands need to audit mobile redirects to discover them before Google does. Make sure all your desktop URLs are redirecting to an appropriate mobile paged and have the appropriate flags.?

Fixing the problem
The problem of redirects can be difficult to fix, requiring an audit to identify any mobile redirects, the creation of a redirect map and the implementation of server changes.

Still, brands would be wise to address the issue now before the holiday season kicks into gear.

It is issues such as this that are increasingly pushing marketers away from m.dot sites and towards responsive Web design, which can be easier to maintain as opposed to having to hand-code all of their pages for mobile, per Mr. Klais.

However, responsive Web is not necessarily the answer as it can result in slower user experiences on mobile.

?This summer is a great time to address this stuff,? Mr. Klais said. ?Take the next few months to do so before the code freeze hits in the fall.

?If mobile search is a strategy for holiday, you have to nail this because it will make it more difficult for people to click.?

Final Take
Chantal Tode is associate editor on Mobile Marketer, New York