1. Buffy has killed around 2100 vamps, if she slays once a night.
2. She has showed a capacity to kill the strongest of Vampires.
3. The Number of humans in Sunnydale isn't that big, and Vamps have to feed on something.

If I was a Vamp, I would figure out to leave Sunnydale. Less predators and more food. This Hellmouth must really be worth something to stick around and get hunted while feeding on limited food supply.

The Math: Buffy kills 356 vamps on average a year, probably more. Each Vamp needs at least one meal, every other night to stay healthy, say, about 150 kills a year. Where are they getting this food? Sunnydale isn't that big.

Sunnydale is big enough to have twelve cemetaries, you know. ^_^

I'd be willing to bet that the Hellmouth renders it easier for a demon to exist in Sunnydale than anywhere else on Earth. Like, mystically and all that. If I had created the Buffyverse, I'd have set down that it takes a certain amount of magical energy for a demon to stay in our dimension. However, this isn't a constant, and could be higher or lower in places. Then it would be logical that the Hellmouth, being a portal to another dimension, makes the amount of energy a demon has to expend just existing lower than it is anywhere else. This way vamps and other demons can turn their strength to, like, spells and stuff. (This would also explain why the Mayor chose to Ascend in Sunnydale -- because it was less energy-intensive than doing it somewhere else.) But I'm not Joss.

Or it could just be that vampires are •••••• and think they can take a Slayer.

Well, if a (formerly) simpering poet like "William the Bloody" can successfully take on two slayers by himself, it should be easier for gangs of them to take on the current one. (Maybe Giles and the Scoobies do serve a purpose after all -- Nah!)

Why Vamps don't organize?: They seem to live by power. The only beings they have loyalty for are their sires. Everything else, it's kill or be killed. They don't organize because they don't trust each other.

The Hellmouth makes life easier works for the demons, but the Vampires are part human and should be able to live in this realm or the demon realm without difficulty, as Angel did. The random vampire in the street should hightail it out of Sunnydale, and let the elder vampires tool around with the slayer.

And that should be "Sunnydale is big enough to fill 12 cemetaries."

Okay, so most of the characters on Buffy are window dressing. I mean, Does every character besides Buffy really need a girlfriend? And what's with college? Talk about not being committed to something. Did that even have a point, or were they seeing if they needed a academic setting?

This would also explain why the Mayor chose to Ascend in Sunnydale
--Matthew Patterson

The Mayor seemingly founded Sunnydale, according to Enemies:

"Faith: He built this town for demons to feed on and come graduation day, he's getting paid. "

Of course, the Hellmouth was there before Sunnydale was. If my theory is correct, then he'd have recognized that and built the town as a place for demons to come have fun, because it's easier for demons to have fun near a Hellmouth.

>Sunnydale is big enough to have twelve cemetaries, you know. <

My community is surrounded by cemetaries. There's actually more dead people here than living! Something to do with government regulations regarding the size or number of cemetaries in any one county caused all the cemetaries to be located near me, since my community is on the border between two counties. Size of the town doesn't have a lot of relation to the number of cemetaries.

I know. It was just a joke. Sunnydale always seemed like rather a small town to me, actually.

Actually, I believe in one of the episodes (perhaps even Welcome..or the Harvest), there is mention that the vampires are attracted to the hellmouth. SO looks like it's possibly not of their own volition.

In several of the episodes of the first season Giles points out that the Hellmouth is a convergence of mystical energies and thus a "hotspot" for demons and those of their ilk

I think I heard Willow in graduation day asking "Why do demons keep coming here anyways." It was during the walking away at the end.

It should be clear by now that the vampires keep coming to Sunnydale because The Bronze serves excellent buffalo wings, which make a nice appetizer before consumption of human blood.

Actually, since Buffy arrived in Sunnydale, I think fewer vampires, demons, and other monsters have been coming to Sunnydale as time passes. It seems natural to me that over time, word would spread throughout the underworld grapevine that Sunnydale was The Slayer's territory, and that would make more of the minor bad guys shy away from the town, despite the draw of the Hellmouth.

The demon bikers in Bargaining are prime examples. When the vamp "invites" them to Sunnydale they refuse because of the Slayer, but as soon as they find out that Buffy is gone and a robot is patrolling in her stead....

It's not just the buffalo wings. Apparently at least one vampire enjoys the 'onion thing' that one of the bars serves.

Seriously, though, it's been shown that not all vampires kill to feed. More than a few routinely raid Blood Bank trucks for a snack without the hassle. Also, there definitely seem to be people who voluntarily allow themselves to be fed from (like Riley).

The fact that Spike has on occasion eaten buffalo wings and the "onion thing" at The Bronze raises the issue of what happens to non-blood food when a vampire ingests it. Does it pass through a vampire without any part of it getting digested? Can non-blood food provide any nourishment to a vampire? I don't have the answer.

Yeah, that would explain why the last real villian was a Hellgod, and why most vamps have been the bottomfeeders. Although, Buffy has never made clear what the external demon population is.

John Ford was asked by movie critics after his Western masterpiece "Stagecoach" was first shown in theaters a rather obvious question: "Why didn't the Indians just shoot the horses?" Ford replied in typical Ford fashion: "Because then the movie would have been over."

My Own theory on how Sunnydale has enough human Happy Meals for the Vampire population is simple. There's a vibrant and attractive job market in Sunnydale. People keep moving in (to die). Sunnydale's always needing new school teachers, coaches, principals, bouncers @ The Bronse, magic store owners, college profs, museum tour guides and specialists. The Want Ad section of the Sunnydale press must be as thick as the obits. Hence the waves of people who should know better coming into Sunnydale.