Yes it is
Gold selling is Highly against the WAR TOS and if its able to be proven through advertisement or other such the CSRs will instantly ban those accounts.
Use the ingame reporting system to report those that do it. Most of the time the GMs are pretty quick to pick up on them, but if they are slammed it gives them a means to go back and look at teh logs.
Ummm... "pretty quick" is an interesting euphemism. I report gold spammers as soon as I get a message from one (btw, the best way to do this is to report it as harassment along with the spammer's name and what web site they are spamming for), but I rarely seem them get banned within a 4 hour window. For a game that has GMs available 24 hours a day, that strikes me as downright lackadaisacal. The ONLY way to beat the gold spammers is to have a mechanism that utterly destroys their ability to use an entire account in less then 30 minutes, since they can rarely make any meaningful income if they are having to buy accounts that fast. Anything else, such as blocking messages that include known gold selling sites, while important, is a band-aid. On Sea of Claws there is one spammer that is spamming for two different gold sites (and at least 3 different gold spammer sites being advertised)!
What blows my mind on this issue is both Mythic AND EA have extensive experience in this area and ZERO attention was paid to dealing with it at launch. It is, without a doubt, my largest disappointment with the game.
What would I have done:
1) I would have made a chat system where player names are "clickable" to pull up a menu of options, such as /t, /partyinvite, /warbandinvite, /addtofriends, /ignore, /report, /reportspammer. Being able to click on a name to report spammers is important, because most people are too lazy to go through the process of creating a full TOS violation report.
2) If /reportspammer is selected, the name would automatically go into a special /ignore list that is in addition to the normal /ignore list and the text associated with the /reportspammer is put into a server side file for tracking purposes.
3) Once a minimum number of unique reports (20-100) /reportspammer within a certain amount of time (30 minutes, typically), that toon is silenced until a GM can check the logs. If it is a spammer, the account can be banned. If it isn't a spammer, and it looks like people abusing /reportspammer to silence another player (such as a guild leader during RvR battle), appropriate actions can be taken against the people doing the reporting. Once an account is banned or cleared, the names are removed from the special /ignore list so if that name gets re-used by someone else they won't be wondering why no one answers them.
This may be similar to what other games are doing, but I don't know of any that go that far.
Whaddya think?