I think in the long run, I come out ahead supporting my local running store more often than online. First - they offer free in-store registration for a TON of local races. I just dropped off the forms for a local turkey trot last week -saved probably $10 in Active.com BS fees between me and my husband, plus I got to pick up our bibs at the same time.
Also, this same store offers 10% discount for track club members, so to be honest, the prices come out about the same on a lot of things when you use that.
There are some times where my fav shoes are cheap online, or I just want another pair of shorts or such, and I'll buy em and save a buck, I admit it. But I do try to go to the running store for most shoes, sports beans, salt caps, etc.
The bigger is is just the options we have today...There are times I've waited on shoes to come in from my local store, and times that I've figured, heck, I'll go online... but that's not running store specific. I've had the same back and forth for a variety of stores/products that might not happen to be in stock (yep, even Macy's/Target types sometimes don't have my target item in my size from time to time in their bricks and mortar).
In general, I like having local running stores in the community, and to keep them there I'm willing to spend an extra buck to try and buy more of my stuff there than elsewhere.