Free seems obvious, and it is in many ways, but there are a few pointers to note.  Teachers, perhaps sometimes more than others, can be suspicious, and will need to be assured that “free” doesn’t involve giving away out-of-date stock or programs, and doesn’t come with any hidden requirement to purchase something else.  

Also because the notion of “free” is so obvious a selling ploy it has been used to death, and so the advert really does need to be carefully crafted to ensure that benefit of the free offer is clearly explained, and that the “free” element is clearly new, unusual and worthwhile.  Free delivery really doesn’t do too much as a selling point these days.

“Open questions” are those which cannot be answered yes or no.  To work, the question needs to be interesting, and create an immediate desire in the reader to know the answer.

Thus, “Would you like cheaper IT equipment?” is neither open nor interesting - the answer is obvious.  “What is the most effective way of taking all your grade D students up to a grade C at GCSE?” is an open question, and one that is challenging. The reader might feel he/she knows all about teaching and learning, but will still be drawn in, just to see what you have to say.

Quirky means unusual, and with a hint of humour.  It doesn’t, however, mean telling jokes or drawing cartoons. One of the most effective adverts I have ever written was sent to heads of special needs in secondary school and had a headline which read:

Ths s wht t fls lk whn y r dyslxc

The piece then went on to explain that the best aids for dyslexic students are created from an understanding of what the world is like for those with the disability.   Many readers commented very positively on the headline; no one took offence.