Do you expect Agent to sell as well as GTA IV and GTA SA?

[Kantor]

Agent is GTA with an E and an N

See, AGenT. AGT = GTA.

However, the letters E and N can only help sales. MGS4 has E and N in the title (mEtal guNs) and CoD4 does (modErN), and even GTA IV (graNd thEft). rEsistaNce, assassiN's crEed...all of the best selling PS3 games.

So, yes.

EDIT: And saN aNdrEas had an extra E and two extra Ns, and that is why it sold better than GTA IV. vicE city had only one e, so it sold better than GTA4 and GTA3, but not as well as San Andreas.