Why do advertisements use both facts and opinons? What effect does it have on the reader?
The opinions are there to appeal to the optimistic nature of readers who share those opinions. The facts are there to make optimistic readers who want to believe that the opinion is being stated as a fact must be a fact because it’s there along with a definite fact on the advert. Putting them together draws the interest of certain readers and sells the product/idea to them by appealing to their wishful thinking. It’s also the same reason why everyone else finds the ads silly at best. If you can recognise the opinion as merely an opinion, and even more so if you disagree with it and then see it next to a fact you will see through the trick and most likely be put off the product. But then advertisers know that you can’t please everyone all of the time, there are some people you won’t be able to please ever, so it’s far better to please some people some of the time than to go for a generic approach that may well end up attracting no-one at all.