@Rogue ColmI guess one factor might be how long you've been here. While not true in all cases, people who have less days on their account aren't seen as on the same level with someone who has more and thus would doubt you're ability to GM properly or keep the RP under control. Now, before you start scream at me, just remember I'm not saying you're bad at it or anything, it just a possibility, no need to kill me for it.
It could also be the timing or the topics you choose. RPGuild is like the stock market or fashion, there are times where people rapidly join RPs and certain subjects are "in season" and other times where people stick to their current ones or subjects you choose might be a bit too obscure for people to get into.
Some mediums are also not quick as easy/appealing to RP as due to things like demographics. For example, CoD is hugely popular, but on RPGuild its not because it usually takes a level of mirco-ing which the younger audience CoD appeals too won't understand and the people who can wrap their heads around it aren't interested in the subject. Most often single player games like Bioshock or Dishonored or RTS are hard to pull off since they don't really cater to a whole lot of people while something like WoW or Fallout has greater appeal since it allows for a greater diversity of character at least in my experience.
If you're using homebrew worlds, that might also be an issue since people tend to get picky over that stuff along with a whole bag of stuff and balancing it can be difficult. Make it too hard or complex, people are shunned away, make it to simple and people scuff it off as bad world building.
Post creation itself might also be an issue as simple lines of text or walls of text have the same effect as homebrew worlds that I stated above. I suggest you try and mess around with the BBCcode to make some interesting Int Checks, pictures also help especially if you can make your own with PS, paint, etc. Put in an CS, use hiders to make it look less intimidating, add some color or font sizes or pictures to make it pop.
Final note: Spamming Int Checks or OOCs is also an act generally looked down upon so I recommend waiting for sometime between checks and stuff and going into other RPS to get experience, make friends, build a reputation, and see how they made their First OOC posts since they tend to be well formatted and can be used as templates for your own Int Checks. Even if it takes extra work, pretty Int Checks and OOCs tend to go a lot further than simple text.
Good luck mate.
