I don't think perps like this are stupid. He'd know better than to act inappropriately toward this person. In spite of their seemingly "uncontrollable" desires they do have some control. And who is to say he wouldn't have targeted her if he was alone? OR that being around this woman's "beauty queen" of a daughter didn't set something off in him?
It was said that he allegedly purchased videos and I believe it was allegedly around 5PM the day AM disappeared. Not sure if that is accurate but if it is I don't think he would have or would have had time to go home and watch the movies (thus setting him off for some sexual crime) and then go out and find a victim, IMO. I think he stalked her personally. I don't think she was chosen as victim in a completely random manner. I'm seeing this as a bit more calculated, although not quite so careful the he didn't get caught.
I agree that it likely has no significance in regards to his criminal behavior.
I agree about not going after the employer's daughter. He would be smart enough to know not to go after anyone connected to him, especially after all the Sara Clark (spelling?) harassment he endured.
I also agree the *advertiser censored* is irrelevant. He was there, he bought some movies. He was simply doing his thing. Probably not related to following AM. However, unless UB called LE about the video footage on their own, LE has something from there connecting him to AM, like a receipt or even the movies in her car. Most likely a receipt found with date and time.
I don't know if he was stalking AM before the gas station though. He may have been and that could be part of the evidence LE says they have that proves this their man. I have no idea what they have, but if they are certain, it could include internet and/or cellphone activities connecting him to looking at AM's many accounts.
ETA: Scratch the idea that a receipt or anything he purchased was found in her car. According to this article, FBI was going door to door to the shops and that is how they found out about his Saturday evening purchases.
http://www.nbc29.com/story/23118650/tracking-down-abduction-suspect-randy-taylor