We summarize 12 experimental methods that have been developed for profiling gene expression by focusing on the 3'-end of poly(A+) mRNA, distilling both common and unique features. Of this family of methods, we provide detailed protocol for MAPS, a method we believe is the simplest and most cost-effective for profiling gene expression and quantifying alternative polyadenylation events by oligo-dT priming followed by random priming and deep sequencing. This method also enables library multiplexing by using a set of bar coding primers during PCR amplification. We also provide a general guideline for analysis of the data generated by MAPS by using the software package maps3end.