Well, this is what I do for a living as a consultant in the entertainment industry, so here is some humble advice that I would offer. Facebook is defiantly something that you should have. Twitter is another good service to have in your arsenal as well, but use it more for instant coupons or updates. That will get people to follow the service, but if the majority of your time should be focused on Facebook and promoting your page. Get people to share it with their friends and stay active with it. I keep seeing haunts that get the Facebook page and Twitter account and the last thing they posted was in November. If you want your user base to stay interested in you, keep the content flowing and make it quality content that people will want to share. That's what helps with your exposure and getting people interested. If your just throwing crap up on the page, you'll end up hurting your brand and you will lose your followers.
Also, if your interested in reaching your guest in a year round fashion beside via Facebook and your website, you may want to consider providing them with a mobile app for your attraction. With over 90 million smart phones out there and the numbers of iPhone / Android / Windows Mobile users continuing to rise, providing your brand with a mobile app is something everyone should consider. Is a great way to keep people interested in your haunt, they just have to push a icon to get your content, you can send instant notices to their phone during the haunt season, and 50,000 other advantages. My company provides haunts custom branded iPhone Apps for haunted attractions and we will soon be offering Android and Windows Mobile apps for haunts as well. We charge a small monthly fee so haunts both big and small can get a App for their attraction. If your interested in it, you can find more info about the service at http://www.hauntapps.com.
At the end of the day, it's more about your strategy on how to keep people interested in your attraction. My advice is to start thinking about the content that you need to generate and how to keep people interested in it. While Facebook, Twitter, and Apps are great ways to reach people, they are just tools. In the next six months, another great service will come along that you will have to start using. But, your message and content is what is the most important thing and it should be crafted well. A lot of haunts I see fall in the pattern of just advertising the month before halloween and that's it. Start crafting your brand's image and developing a marketing and social plan that engages your guest year round using those tools mentioned about and don't let up. That way, when the Haunt season opens up, they have 11 months of anticipation built up, they will go to your Haunt first before anyone else. I see a ton of people and companies get more caught up with "What's the Big Thing Right Now" and ignore the content they are pushing. Always remember, "Content is King".
If you need some help, drop me a email at movierelics at gmail.com or visit my website and drop me a note there. http://www.charlesterry.net