Giving has always been advanced as one of the ways with which you can gain. One would say that it is a selfish way to be generous and in this case it is. You give likes so that you can gain followers. Unlike using free followers this would require you to exert more effort in the process. It is more beneficial as you get to acquire real live followers who really boost your account.
First you need to identify your target. This may be people who have same interests as you or people who are potential clients for your business. You like their pictures and their posts on a regular basis. Don’t like pictures from years ago so as not to appear as a stalker. Ensure you like their new posts and the most recent ones. This will get their attention and they are bound to follow you in order to get more likes from you. This way, you will have spent no money and would have gained free followers. It may take some time though so you will need to be patient.