Does etiquette have a place in the world of on-line dating?

Of the 14 people who have 'flashed' me as of this morning:

• 4 of them are way too young for me
• 4 of them live too far away
• 4 of them have not said what they are looking for, which makes me think that they don't care and just want to get their end away
• 2 of them I plan to contact

So, what am I supposed to do about the 12 I don't want to interact with? Should I write a nice little e-mail à la Emily Post (who, by the way, does have etiquette guidelines, but for teen-agers)? Is it ok if I don't respond to each and every flash?

Side note: this meetic thing is excessively time consuming and I've decided not to spend anymore than one hour a day on it!