Fact#1: your local bike shop (a brick and mortar physical establishment with overhead) cannot compete with online price slashers who have the upper hand by dealing in volume.
Fact#2: your local bike shop usually makes more money on *servicing bikes than selling parts or bicycles. *Service = mechanic (a person with the aptitude to fix a mechanism).
Fact#3: There are a lot of self proclaimed mechanics or 'certified' mechanics who really don't know crap. They work at a lot of LBS's and cost less than really knowledgeable mechanics.
Fact#4: The really knowledgeable mechanics or cycling artisans who know how to fix your bike and work the magick (oooh... aren't I new-age) are very few and far between because those mechanics either:

• have a S.O. who is a professional who can pay the bills so they can afford to be an idealistic bike mechanic
• live at poverty level in a commune
• work in IT or some other far more lucrative career and only work Saturdays at the LBS to feed the soul which has been compromised elsewhere in a Charlie Christian kinda way for their 'career'.

Basically the internet=monetary savings on parts where as the LBS=service (or a flesh and blood you can blame if your s*** doesn't work as expected).