Like any investment, there are advantages and disadvantages to investing into Tax Liens. However, one of the advantages of buying a tax lien relates back to a property being redeemed.
If redeemed, you investment could earn a high rate of interest. While each state has its own rules (which can be a disadvantage to an individual investor, such as a retirement plan), one might find of interest that tax liens in some states pay interest during the redemption period of up to 18% (maybe more).
But, it may even get better. Buying a tax lien property also means you may be able to secure a property for well under market value.