Bill and any other advertiser are free to turn their glidersource.com ads on and off at their discretion at any time, for any reason they choose. Maybe because they're going on vacation, maybe because they want to conduct some marketing research, maybe because a sale is pending.
Adds turned off (or "paused" as I call it), can be turned back on without loss of content, emailing anyone, or having to comply with a world-domination policy.

Sean: Am I surprized Tim didn't take me up on the web programming offer? No, but it was sincere, nonetheless. Still, for the sake of sailplane shoppers, I hope he can figure out a way to sort, index, or categorize the nine or more pages of aircraft ads.