Do surveys help book sales?

Everyone said it, but I didn't really believe it. Now I think it may be true. The book world is changing. What brought me to this momentous conclusion? I've been looking at Alison Morton's  survey :
http://alisonmortonauthor.com/2015/02/what-the-readers-say-the-survey-report/

and I did not see library or bookshop mentioned anywhere. I shall go back and read again just to be sure I didn't skim over the words. Skim reading is a diabolical habit of mine - so often I miss the important bit and have to go back and find it!

I think I knew the worst about video trailers. Hardly anyone watches them and that is a pity because, like Alison, I enjoy making them. I did the first one six or seven years ago when I knew very little about the process, and didn't own Photoshop software. Off and on over these last few weeks I've been editing photographs in order to make a trailer for Abduction of the Scots Queen - but now I think Why Bother? Then my other side kicks in and argues Why Not? I've done a fair bit of work on the pics so far, and I may as well garner  what I can from what now seems to have been a time-wasting project.

I must take down few video trailers  I have up on You tube. They look so amateurish I cringed when I checked them today! Or maybe I can re-vamp them somehow. Strangely enough the worst one has the largest view count - perhaps people recommended it as what not to do!