I think the SEM is killing the SERP, perhaps one reason among many others that people are going to social media.
Have you ever thought why Yahoo and MSN are losing steam so Google? My theory on that is that people are saturated with excessive SEM.
Is there an alternative to search engines? Well the first thing people are doing when they are looking for something specific is search.
Do you remember how people searched before internet? The majority used the yellow pages.
Do you remember how people bought products with catalogs from long distance before internet? The mail orders.
Do you remember how people educated themselves before internet? Public Libraries
Now all you have to do is own a computer and use an internet connection to have acces to all of that. The problem is people are getting tired of being sollicited every single second when they are surfing on the internet, even when they use a search engine to find something specific.
As long as men are free to ask what they must, free to say what they think, free to think what they will, freedom can never be lost and science can never regress.