Happens all the time. Last few times I've purchased electronics on Amazon that have been relatively recently listed (i.e 20 reviews or less), I've made a point of looking at the reviews.
Click on first reviewer's name, and that reviewer has just happened to review 5 items all on the same day, and those are the only 5 items they have ever reviewed. And all 5 items are completely random (electronics, bed linen, garden equipment, clothing, etc). Rinse and repeat with second, third, fourth reviewer and a similar pattern arises.
Majority of recently listed electronic items that I've been looking to purchase follow the same pattern.
You just described my reviewing behavior, and mine are legitimate reviews. I buy a variety of products. My purchase history is listed in my account, and every once in a while I go and review a bunch of them at the same time, in reverse order of purchase because that's the order in which they appear.
Click on first reviewer's name, and that reviewer has just happened to review 5 items all on the same day, and those are the only 5 items they have ever reviewed. And all 5 items are completely random (electronics, bed linen, garden equipment, clothing, etc). Rinse and repeat with second, third, fourth reviewer and a similar pattern arises.
Majority of recently listed electronic items that I've been looking to purchase follow the same pattern.