There are some gems of advice in this thread. [@BangoSkank] good job updating the OP to include them.

Just to jump in with my personal experience... A few months ago I celebrated my [u]one year anniversary[/u] of joining this forum. During this time, I have been part of... 
[h3]33 RPs that died![/h3]
That number is [i]only[/i] the RPs that made it passed the planning stages, and there are probably more I don't remember. Some are groups, some are 1x1s, and one I even GMed myself. [s]Shoutout to ERode for bringing up Windfall which is [i]not[/i] dead![/s] I think the most important thing that's been mentioned so far is what Rapid Reader wrote: 

[quote]You have to ask yourself, "what does success mean for me as a GM/RPer"?[/quote]
For me, it's 100% about having fun, so as long as I had fun while the RP was active, that's what matters to me. I understand this isn't a sentiment shared by everyone, so now I'll share some stuff that attracts me as a potential player to people's roleplays, to help people looking for what they can do to attract more people and achieve the success they are looking for. I'm sure some of this has been mentioned already in the thread but bear with me.

Presentation is very important. That doesn't mean a lot of fancy bbcode, but it does mean taking a moment to present your ideas in a clear, concise way. For example, a large wall of block of text can be a big turn off, but breaking that wall down into multiple paragraphs is already an improvement to help with information digestion. Also, [i]less is more![/i] Especially when it comes to 1x1 checks, not to come off rude but... no one needs your life story. Make your RP ideas front and center, at least! 

Passion for an idea can show through your interest check, so make sure you put your heart into it if it's an idea you really want to try, and [i]don't give up![/i] Even if it's a more generic idea, if you show you're serious about it, you'll have more attention.

As far as reputation goes, you'd be surprised how far a name and avatar change can go along with a dedicated plan to turn over a new leaf. If you're worried about your reputation putting people off, try on a new "brand" so to speak and work to change it, especially by reaching out to others. They say you get what you give, so joining other people's checks will give some good karma :lol

Edit: there are some interesting things to read in [url=https://www.roleplayerguild.com/topics/183042-simple-question-what-kinds-of-rps-do-you-guys-like/ooc]this thread[/url] too about what people are looking for that may help with getting interest!