In my vast experience as a young woman, I've come across a variety of creepers. I would say I've been getting creeped on for at least these past 7 years, and I don't really see an end to it. Just in my past few months working in a book store in the local mall, I have been able to study the creeper up close, by hiding behind bookshelves, talking to them, and examining their purchases. Thus are my observations:
There are three basic kinds of creeper that inhabit book stores (and I believe this to be universally true):
1) The Old Man--This variety of creeper walks in, often carrying yesterday's newspaper, and begins wandering around aimlessly. When asked, ever so politely, "Hi, can I help you find anything today?" their answer will almost always involve the history section or a book of crossword puzzles, large print edition. After you help him to locate this particular tome, he entraps you in conversation, asking you pointless questions about your college and major and other sorts of things. Then he will talk about the book he has just picked up with you for another 10 minutes, incorporating bits of irrelevant facts about his life into the conversation, like he thinks that by telling someone that he used to be a professor at a college earns him hottie points or something. At the end of your interaction with him, he will lean a little closer than you'd like and tell you that you are "a lovely young lady" and that he thinks you will go far in life. This is old person code for "I think you are attractive." Now you know.
2) The Foreign Guy--Much less subtle than the old guy creeper, this variety of the breed is the kind that is unavoidable because of his overbearing need to express to you your attractiveness. If he does, in fact, speak English, he will insist on telling you that you are pretty, and other such compliments. He will compliment every girl that works in the store, so that no one feels left out. When he leaves, often with wife and several children scooting along behind him, he will say something like, "Goodbye beautiful ladies!" and wave. If the man does not speak a lot of English, he will simply smile at you a lot, and appear to be especially grateful for you help. He will say thank you especially genuinely, and add a blinding smile and some lingering eye contact for the extra creeper effect. Now, this may be appropriate where you're from, foreign guy, but in these here 50 United States, we don't go around randomly complimenting women (no matter how much they deserve it). Not that we aren't appreciative of the extra attention, we are, but instead of making us want to run lovingly into your often-mustachioed arms, we mostly just silently file the compliments away in our brains, and heave a sigh of relief after you have left us alone.
3) The Nerd--Now, here's the kind of creeper that is the most difficult to get rid of. These attention-starved, often mediocre-looking guys will not only be surprised that you are addressing them (until they realize that it's your job), they will be astounded that you may know just as much about a subject as they do. Well duh, I work in a book store. Of course I know about books, even if they are mystery/thrillers or science fiction. While it is good to give every customer direction and help, the Nerd is not one that you want to spend a particularly large amount of time assisting. The longer you hang around them, the more likely it is that you will hear something about that that you wish you hadn't, such as, "Oh, I see you have a mosquito bite there, you should have seen my legs when I went camping a couple weeks ago near a swamp, they were just covered in insect* bites." Then he will proceed to pull up his cargo pant leg and display the scars. Like the Old Man, the Nerd will ask you a variety of questions to keep you involved in the conversation, but with less self assurance and more awkward pauses where you are trying to think of a reason why you really must get back to the register right away.
*a nerd will always say "insect" rather than "bug," with the scientific nature of the word appealing more to them than the alliteration.
Well, there you have it. A complete guide to small book store creepers. I feel as though I should do a full-edition version of Creeper Varieties, kind of like that "douche-bag" book, that goes over every type of douche-bag that there is, but my space, and your time, are limited.
A note to the creepers mentioned above, you are all valuable customers and we appreciate your attentions greatly, we just get a little skeeved out by you.