My direct answer to the question is, at present, (rhe last three months) between 85 and 90 percent of our direct enquiries turn into bookings. When we started 15 years ago, for the first three years we got a conversion of 95 percent. However is you are analysing "page views" to bookings, this is about 3 percent and has been since we started (I am not counting bounces or robots in page views).
But - things are changing fast and another "sea-change" is, I predict, about to happen.
My work and activity over the last 15 years and therefore my understanding, thoughts and comments are based only on Internet marketing. Since 1996 I have only used the Internet to find clients for our rental accommodation in France - Holiday apartments and now B&B..
At first there were no rental listing sites, so I invented my own. The browsers were slow and erratic, so we kept things very simple. Search engines did not exist, so we listed in directories.
There have been a lot of changes, but basically things are just the same. The bottom line is that..."There ain't no such thing as a free lunch".
What I mean is that at first I was up until four every morning learning to create websites and to get them seen. Today, to keep competitive, I have to continually learn new skills and techniques to get clients. At the moment I am struggling with HTML5 to get an understanding of Microdata (
http://dev.w3.org/html5/md/ ) - so back to some 4 am nights :(
The alternative is to farm this work out and to rely on advertising sites - but my experience suggests to me that things are moving so fast that the "experts" are always behind the techniques which work. For example, advertising listing sites like VRBO (I was once bigger than them) are no longer as effective as they were and are losing ground to PPA (Pay Per Action) sites like airbnb.com.
Search engines are morphing into mobile "apps" - computers are morphing into phones/tablets/readers - all "search" is getting local and personalised. Social networking techniques are getting me more enquiries for our own B&B than traditional SEO, for example I got more feedback (and thus bookings) from Pinterest than Google Places last week, and I work hard at Google and have hardly started on Pinterest.
I realise I cannot now do the necessary marketing, development and technical work on my own, so I am trying to get a self-help group of like-minded people to get together to form a co-ownership team for promoting our accommodation businesses (B&Bs, Gites etc) - to start something rolling I made a little site at
http://wikibnb.org - all it is doing at present is to offer a free one-way link to any relevant website (and that is just about everyone) - I hope to be able to form ways of structuring mutual help for development, marketing etc.
This is not a plug for this new initiative - I would hope that James will benefit from this sort of structure through advertising and visitors - perhaps SF can be a discussion forum for us French accommodation providers.