How you write your advertising copy will be based on where you will place your ad. If it’s a billboard ad, you’ll need a super catchy headline and simple design due to the speed at which people will pass. Online ads are similar; consumers are so inundated with Internet advertising that your ad must be quick and catchy.
“If there's one thing you learn by working on a lot of different Web sites, it's that almost any design idea--no matter how appallingly bad--can be made usable in the right circumstances, with enough effort.”
What would the consumer gain by using your product or service? This could be tangible, like a free gift; prestige, power or fame. But remember: you must be able to make good on that promise, so don’t offer anything unreasonable.
Magazine advertising is the most versatile, but this is solely dependent on the size of your ad and how many other ads compete with yours.
Grabbing the consumer’s attention isn’t enough; you have to keep that attention for at least a few seconds. This is where your benefits come into play or a product description that sets your offer apart from the others.
If you have a full page ad, feel free to experiment; more page space gives you more creative space. If the ad is tiny, you’ll need to keep things as simple as possible.