It's amazing what you can learn from statistics. I've just been transferring my database from one computer to another and as a result I had to sit and look at various tables and charts I'd never really bothered with before.
The first shock was to realise how much longer it takes to find a home for a long story than a short one. Of course this is one writersr's experience only, but I was surprised to find that work under 1000 words takes an average of four months to find a home, and is seen by between one and four editors before it does. Work over 6000 words however, can still be sitting on my hard drive a year after I write it, and may be rejected by up to eleven editors before either placing in a contest or making it into print.
The second shock was that I've never had a completed piece of erotica rejected! Of course, I write most of it for markets that actually commission the work from me, and for editors who know me and with whom I have a good relationship, but even the first piece I've sent to a market new to me has been accepted. Are they so short of work, or am I so good at working out what they want? Who knows?
The third shock was that fiction over 8000 words doesn't seem to place at all unless it's genre work. I've found homes for five science-fiction/fantasy stories of between 8000 and 15000 words, but only one piece of literary fiction over 9000 words has made it into a print market.
I'd love to know what statistics other writers have on their work.
In the meantime, if you want to know how long a market takes to respond, google 'The Black Hole' for sci-fi publishers and/or 'Duotrope's Digest for the literaries. It will help you decide how long to hold your breath and cross your fingers for!