Choosing to run the ad for several weeks is a smart business decision. Sometimes it takes awhile before you get calls/results to your ad. Running a smaller ad for a longer period of time over a one time "large" ad is good!
DON'T do what we call "running the Lord's Prayer on the top of a pin." In other words, don't try and cram every inch of the ad with text. Make your point in as few words as possible and highlight and bold the points you are trying to get across - your business name, what you are selling, and your contact information (since it's an internet business, you obviously won't be supplying a physical address for your clientele to visit but make sure you have a phone number, email address or website site prominently placed on the ad).
If you have any space - ask for some artwork that pertains to your service. Ask for a catchy border that will attract the reader's eye.
Don't be shy in asking for a proof before the ad appears in the newspaper -- and don't be afraid to tweak the ad during its run.
You could also ask if there's a chance that you might get a little editorial write-up to help promote your business. Sometimes you have to have an advertising contract for certain period of time or for a minimum amount of $$$ spent, but it never hurts to ask.
