Well, FireCat, as Azmodai explained, on the forums it CAN be slow, as a lot of people are not able to be on permantly, and when they do, may only look at RPs that they are currently involved in, mainly due to a lack of time.
This factor is especially prevalent at the moment as a lot of people are studying for finals and various other exams, so have a VERY limited time online.
In regards to new RPs, it does take a while to get interest up, but you could advertise on the
RP Advertisements thread, which will bring attention to the RP for you.
And, in regards to the chat, at the moment, for similiar reasons, it does have its slow moments where it is very quiet, especially for me, being the UK and what not!

However, in the evenings, US time, there are usually a fair number of people on there who would be happy to RP.
Due to the very nature of the two RPing media, chat style is much faster in progressing, but the forums allow for much more detailed posts etc.
I would recommend the
Chat RP if you would like something a little more fast paced, and as Azmodai2 said, it is a good place to have a chit chat and get to know a few of the people.
It is also probably the quickest and easiest way of getting hold of staff members - I know that myself and Eric (Ramaeus, the owner of the site) are on there all day every day in general.
So, really, just have patience, the activity will come in time for your RPs, it just takes a while.
But keep up the good work, we are happy to have someone as proactive as you.
Any more questions, do not hesitate to PM me on here, or chat to me on the site's chat service.
RPGateway Moderator and RP Academy Principal
~Lord Saladin