It will just Kill your account for life!
Short-Term Issues vs. Long-Term Gains: Almost every new seller leaps into Amazon with their head held high, whilst asking family and friends, and using unverified sources, this is great and increases sales by miles...and it is only a short-term fix.
Long term, your account will be suspended, this is very difficult to get back from. Amazon takes suspensions very seriously. They have initiated several sweeps this year where they have taken down thousands of highly rated sellers for this.
There is a correct way to get a product review. Firstly sell the product. Secondly providing a high-quality product. Third a good customer service. Then if a customer wants to leave a review it will be 5 stars! This will enable you to rise up through the Amazon rankings and meaning you can grow a structural business which can be a sustainable source of income.
There are correct ways and incorrect ways to contact the customers after their purchase. Amazon has a whole page of policies for this and you should check them before proceeding anywhere further along in the review channel!
A final thing to take note of is that Amazon getting wise to the fact sellers also have their products on their website and often forward the customer over to Amazon to leave the unverified review. This is a perfect way to get your account or ASIN suspended.