SEGA has announced a partnership with GameSessions that will allow players to download full versions of SEGA games on PC and trial them. After the trial period is over an option to rent the game for longer will be offered, and the option to buy will also be a choice. It is similar in theory to what EA does through the Access program, where players get a limited trial of a game with the option to buy after with all progress carrying over.
Currently Football Manager 2015, Company of Heroes 2: Ardennes Assault, Sonic Generations, and Warhammer 40,000: Space Marine are the games that are on offer. More will join the program further down the line, but details on which games will be part of the service are as of yet unknown. There is also no information on whether SEGA is considering to launch a similar program on consoles in the future.
Source: Press Release