A lot of websites which put up barriers to entry have been hit in the last few weeks by a new penalty in Google. This applies specifically to the mobile results, and where the initial view on the site is obscured by some sort of overlay, including advertising. It would appear that Google is saying that any site doing this is not being helpful to its mobile visitors, who want information quickly and easily, and if the site is not facilitating that, then it doesn’t deserve to be ranked highly.
I doubt that this affects your website – we don’t tend to obscure our sites with pop-ups and overlays in business – but it does remind me that we can’t expect Google to promote our sites for free if we make it hard to see the information. This includes the simple matter of hiding stuff down a tortuous path of website levels, or even making it completely unavailable without ‘signing in’ or giving up your email address.
I do understand the ‘fill in your email address and we’ll send you the document’ approach to marketing. In many cases, it’s very successful in generating low-quality sales prospects. But just remember that if the content is good enough to warrant people giving up their email address to get it, then it’s probably good enough to attract a lot of visits from Google …if only Google was allowed to see that content.