The week before the AFL Grand Final, Harvey Roman in Geelong put up posters in its shop windows stating:

Buy a quality TV on the cheap - Samsung 55" 4K LED Smart TV - normal RRP $1000 - Manager's offer 20% discount PLUS 1% discount for each point difference in the final score of the Grand Final - first 20 customers only.

Following the resounding victory of the Geelong Cats over the Sydney Swans (133 to 52), Dave was first in line at Harvey Roman the following Monday to buy the television. He walked past the poster at the entrance, grabbed one of the televisions and approached the checkout to get a receipt for the television, as Dave intended to register the TV for its manufacturer's warranty. Jono, the store manager, took the TV off Dave and said: 'You must be joking mate. We are not in the business of handing out free TVs here'. Dave is furious. He believes that Harvey Roman must honour the offer as Dave was one of the first 20 customers in the store. According to Dave, it was Jono's fault not to anticipate such a high scoring victory of the mighty Geelong Cats. Jono argues that the poster does not constitute an offer but rather an "invitation to treat".

-Advise Dave(Please use cases to analyze.)