Thanks for the comments, everyone. You've given me a lot to think about.
Certainly I agree that the ad could be more exciting and enticing, I should be giving the applicant the impression that this is a job that will turn them on and and take them places, rather than just having a matching skillset.
Sure, the salary being offered isn't loads but there's plenty of scope for progression in the company, and this needs to be stated. The salary amount wasn't stated except in the most recent ad, so that's probably not the main reason for lack of response.
Might I get more of a response by being more exact about their experience eg would suit a developer with at least 1 year development experience? Would this be considered a junior role? I'd rather someone with at least a little experience.
I get the point about the broad skillset. It's not that we're necessarily looking for an all in one, but is someone has at least some knowledge or aptitude in at least one of the desired skills that would be...desirable. And I want that applicant to know that they stand a better chance of getting the job than someone without. Would potential applicants be put off by not having the skills listed under 'desired' skills? Perhaps I should be saying 'skills desired but not required'? But yes, when it comes to design skills I should be more clear about what I want them to design ('graphic design skills').
The location is normally included elsewhere, dependant on where the ad is being placed ie the job centre site lists it in the heading, separate to the text.