You are doing yourself a disservice by not practicing under time constraints. Since you did not write this essay under the proper writing conditions, I will not score the essay because that will give you a false sense of accomplishment. I cannot honestly score you on a paper that did not meet the writing guidelines for a practice test. Sorry about that. Writing 300 words in your method of practicing to write is excellent, but bad for an actual test.  
  
You are obviously focusing on the wrong aspect of the test, which is simply to show off your vocabulary skills. You are not really using connecting sentences in your paragraph discussions so rather than creating a cohesively connected single topic with supporting information paragraph, you are writing about 2 separate discussions, which means neither discussion is totally developed in the essay.In the second paragraph, a proper connecting sentence between the two would be a transitory presentation such as; "... spontaneously. This is an act that is encouraged by the manufacturers in order to sell more of their products..."  
  
If you want to know how to shorten the essay, the answer is simple. Don't over discuss it. Either you discuss one topic per paragraph without writing long sentences or run-on sentences or, discuss 2 short but connected topics within the 5 sentence maximum requirement. Aim to write no more than 275 words. With 300, as I always say, you will never have time to edit and almost perfect your presentation. That is why practicing under time constraint is the only way to prepare for this test.  
  
Taking your time to write without time restrictions allows you too much liberty in terms of topic presentation, paragraph development, and editing. Elements that do not exist in the testing center. You will continuously write wordy essays that will prevent you from meeting the time consideration requirements. Long essays are not an assurance of passing the test. Clarity, cohesiveness, proper vocabulary usage, and proper sentence structures are the only assurance of passing the test. You can write 500 words and not have a good essay to present if it does not meet the standards for consideration. That is why I train my students to limit the number of words they write so that they can focus more on the important elements of the presentation. Writing for simply writing isn't an assurance of passing the test.  
  
Please do your best to never again practice without time constraint. You are only cheating yourself and you will not improve towards being properly prepared for the test if you continue to practice in this manner.  
  
I am not going to discourage you from practicing to write essays though. Just don't use IELTS topics for your practice essays. Just pick common, everyday, simple essay topics as assigned to English learners and write about those topics free of time constraints. You can improve your English vocabulary and writing skills that way. Do that type of writing in between your practice test essays. You can even post those free topic essays here for further advice regarding writing skills and vocabulary or sentence structure development. Don't use IELTS topics because those need to always be written under a specific writing set up or setting that does not allow for the same writing freedoms as the common topic ESL essays.