First let me say as an author (even occasional) that I would prefer that my books in all forms be available at all times, at all stores and outlets.
Secondly I can understand a bookseller whether on line or in a store, a publisher, a printer, or a book distributor trying to find the best way to be competitive, make a profit, and indeed just "stay alive." They have to meet many challenges or they will be out of business. I regret Borders closing. I greatly enjoyed Dalton's and other book stores in the malls.
Go here for some sad pictures of closed Booksellers.
http://www.buzzfeed.com/mjs538/portr...sed-bookstores
That said, it comes down to this.
When you have been in this business a while, you have an idea of what is working for you and what is not. Then when someone like Amazon comes and says "I got a deal for you," you listen carefully and weigh the advantages and disadvantages, financial costs and rewards, time commitments, and contract obligations. You also think about the overall picture and if you feel good morally and intellectually about the arrangement and the partner you are signing up with.
It isn't exactly a marriage, but it can be a serious long term commitment to a business partner if it works out, and with that in mind you also check to see how it can be ended relatively painlessly if essentially you and your partner get a divorce. You need to be sure that you are protected by the equivalent of a prenuptial contract.
[[You don't want your books in some kind of legal limbo! That is the first and paramount concern the author should have.]]
Then finally when you personally are satisfied, get a lawyer you trust to check out the contract further to see if you missed something, and suggest changes. I am blessed in that I am able to do these things. I fear that many young or struggling authors now and in the past haven't been so fortunate. We have heard of those cases where music and books were not available for sale though there were potential buyers, or the creators or performers wanted to sell them directly but couldn't (legally.)
As for forecasting the future of the bookselling business, I will say only that it will definitely come, and then we will know what it is. (That is a little tongue in cheek.)