Compare the elements of a producer's marketing mix for a convenience good with those of the mix for a speciality good.
The elements of the marketing mix are product, price, promotion and place. The PRODUCTS are very different and appeal to different target markets.
A convenience good is probably going to be offered in more locations than a speciality good. The marketing mix for a convenience good would emphasize the PLACE aspect.
Which means that the distribution would be broader, the product would be found at more stores than a speciality good which would be distributed to a few special or gourmet stores in neighborhoods where the target market of the product has been identified to live or shop or both.
The other element of the mix that would be emphasized for the convenience good would be PRICE, the speciality good would be priced higher than the convenience good.
Also, the PROMOTION of the speciality good would be limited to subject oriented magazines that cater to that product, like a special wine being advertised in Food & Wine Magazine that is targeted to the demographic identified as most likely to buy the product. Convenience goods would be promoted in lower end publications like newspapers or supermarket flyers.