You wanna try some Flash, kid?

Using Flash in websites is a tricky beast. It's an extremely effective way to get cross browser multimedia content to your users, and add some dynamic elements to your page. Yet it's also easily abused. It can be a fine line between abusing Flash, and leveraging it for your website's benefit. Don't be afraid to use Flash technologies, but be vigilant.

All the kids are doing it

It's easy to get sucked in. You can do so many things in Flash that it's easy to be blinded by it's shiny-ness. Animations, vector graphics, movies, and stuff you almost can't believe. Especially as a client looking to have someone build you your new website, it can be very tempting to respond to an all Flash site. It moves. It plays music and sound effects. It swishes and flows. It's so cool, and you want to be cool. Just say no. Let me lay out a few things you want to avoid.

1. Splash Pages - These are the little animated movies that play before you actually get to go to the site. Usually with a 'skip ahead' link or some such these days, though unsurprisingly not always. Splash pages are terrible for usability. They remove your user another step away from the site, add in a click, frustrate and/or confuse people, and are generally found to be annoying. Nearly all your users will dislike a Splash Page Flash animation. They'll skip it or close the site entirely. How often do you sit patiently watching a Splash Page when there is a skip intro button? If you always watch it, then you're about as common as the people who sit in the movie theater till the end of the credits. Flash Splash Pages are Bad.
2. Whole Site Flash - This is where the entire site, images, animations, menus, content, hundreds of pages maybe, are all contained within a single flash page. The browser doesn't navigate around, all of it is done within the flash. This is tremendously bad. First of all it hurts your Findability and search engine rankings, as there aren't multiple pages on your site with content, which the search engines love. Secondly your user can't bookmark interior 'pages' of the flash. If they want to send some information to someone it's easier to send the link to the page rather than the link to the page with instructions ("OK go to the link, then click on menu, then click on products, then click on 'online offers', then click on $50-$100 then click on next twice, and it'll be the third down on the right, click the image, and you'll see the product details") Why throw up barriers to your users? Oh and it's also generally much more expensive to modify and maintain.
3. Disabled? Tough - Flash accessibility is notorious for disabled users. My next door neighbor is blind and I hear it from her all the time (she has a nice setup with a talking computer and everything). It's made progress over the years, but still, for her, if it's flash it's an immediate page close. Yes, this is anecdotal evidence, but the fact is that if you care at all about Accessibility, which you should because you might be legally required to be, Flash elements can be an issue.
4. Cool Elements For Cool Elements Sake - This is more of a "cultural" issue in that it's not a particularly technical issue, but one of choice. For instance, having music play on your site automatically. Random animations fluttering about distracting your users. Things like that. They look cool and sound cool, but they also turn off most of your users. I wish I could learn why people love this stuff for their own sites, even while not truly realizing they hate it on everyone else's sites. I had one client, Shawn Rodgers Photography, ask me for music on his site. I asked him why, and he told me because all his clients had music on theirs. I had him do an impromptu poll in a few locations about people's feelings about music automatically playing on sites. More than 90% of the people hated it. So why do it? Just because it's cool?

Those are just a few of the problems. Don't get me wrong, I use Flash, and I think it's an amazing technology. I also think that it's one of the most abused ones out there. You should have video and audio options, you should have interesting animations or menus if they're called for, but you need to be cautious with Flash. It can elevate your site to new heights, or drag you down into the gutter. Just be careful.