Hidden links

11 November 2008 - 16:02

Independent software vendors (ISVs) are often pressured into linking back to download sites that list their software. Some sites won't list a software product unless you provide a backlink. Others tempt you with awards you can display on your product page with a link to the download site listing. I don't think there is much benefit to software developers in linking to listing sites. But there is one big potential disadvantage. Download sites list thousands of downloads and there is a good chance that one or two will cause a malware alert in McAfee SiteAdvisor. This could lead to the software developer site getting a cautionary or even a danger warning from Site Advisor, just by linking to it.

The simplest way to avoid the problem is just to not link back to download sites. However, if you still want to link to them, I think that one way to do it without risking getting on the wrong side of Site Advisor is to use Javascript to create the link. It's quite simple.

Instead of using a plain HTML link like:

<a href="http://adownloadsite.com/">Download Site</a>

you use a link like this:

<a href=# onclick='window.location.href="http://adownloadsite.com/";'>Download Site</a>

If you want the link to open in a new page (as if you had used target="_blank" in a normal link) then do it like this:

<a href=# onclick='window.open("http://adownloadsite.com/","_blank");'>Download Site</a>

By linking this way you will not be seen as linking to the download site by search engine spiders, since they do not execute Javascript. This may be considered by some people as a benefit, as you are not giving some of your Page Rank to an external site. From a search engine optimization (SEO) point of view it is comparable to using rel="nofollow" in the a tag.

A disadvantage of using JavaScript links is that anyone who right-clicks the link to open the page in a new window or a new tab will get the 'real' link - the one in the href= value, as shown in the browser status bar. It's a bit of a sneaky way of concealing where a link goes to. Considering all the security scares I'm actually surprised that web browsers still allow this to work, but I've tested it in Firefox, IE6 and IE7 and haven't noticed any problems.

I should point out that I don't know for sure that McAfee Site Advisor does not execute Javascript when spidering a site. I'm making an assumption that it works in the same way as search engine spiders because executing Javascript would be too much of an overhead given the number of sites it has to check. Some people have noted that Site Advisor doesn't give a black mark to sites that do annoying things like resize browser windows. So it's probably a fair assumption. But at this point it is just an assumption. If you want to be 100% sure of protecting your site's reputation, the safest thing is just to avoid linking to sites that might contain dodgy downloads.