Getting banned for any site could drastically affect what you have built for yourself online. You may lose the followers you have gained and also lose the popularity you had built for yourself. This is one of the things that worry most people before making the decision to use the free likes on their accounts. In as much as it is a free offer you may need to be cautious. Using a provider that just uses spam likes could harm your portfolio.
However there are those whose systems have been designed to provide you with the free likes without flagging the system. This is what you should look out for the most. The sites will offer the services in less than 24 hours which quite a catch. The benefits are very tempting but you need to be careful. The social media sites may flag your account if they not suspicious spam activity on it. It would also take time before you are allowed to use your account again. This could also affect your followers who may leave because the spam could be affecting their accounts also.