Hi good attempt Mommmmo .... Hope I typed the right number of "m" s ....LOL :D
However, advertisments still misleading customers in some level, especially those customers who can't make clear decisions. Business tricks and celebrity effects could easily manipulate their thoughts, just like overprice roses and chocolate during valuntine's day.
Pay attention to grammar;
advertisments mislead / advertisements are misleading
In conclusion, the development of advertising industry is still reasonable, customers by goods according personal standard and needs. However, mass media and related governmental department need oversee this blooming industry to make sure it on a right and healthy path.
You need to align your conclusion with the prompt, which speaks of sales reflecting the power of advertising and not the real needs of the customers. As it is your conclusion tries to discusses good and bad about advertising. Instead your focus should be moved to the impact of advertising on sales : )