Imagine your online advert for your holiday cottage is a noticeboard on a busy corridor. Lots of people will pass it. However, if you don't update it at regular intervals people will stop paying it any attention because it never changes and, worse still, is out of date. Nothing will kill a potential booker's interest in your cottage faster than out of date prices, a lack of recent reviews or an empty availability calendar.
You have to update it.
Now imagine that Google is the noticeboard monitor. You may have paid for the right to be on the board, but, the more out of date it becomes, the more Google will move it towards the less seen corners of the noticeboard - even placing other adverts over yours.
Alan Egan at Vacation Soup (a holiday rentals expert in whom we have the highest regard), has published an interesting and helpful article which not only explains, why and how your website will die (if you let it) but what you can do to keep it alive and flourishing.
At My Favourite Holiday Cottages, we have always believed that an Owner's website is the best way to get bookings for your holiday cottage - if only you can get people to view it. That's why everyone advertising their cottage with My Favourite Holiday Cottages has a link not only to their home page of their holiday cottage's website, but to their booking and (where possible) pricing pages. These links are also valuable because they play a part in Google's ranking of your site - especially if people are clicking on those links.
However, fail to keep your advert up to date, clicks will decrease and it will do the technological equivalent of growing mouldy. Likewise for your own website, which must also be kept up to date.