I was happy to see that today I made my first SR-EL sale. I was curious to see what image it actually was. To my surprise it was a photo of one of our cats (similar to the one shown here) that sold 8 times over the course of 2 years prior to selling the rights.
The photo in question had been rejected in many agencies with the reason that the image was not "sharp" enough.
I hope this shows that for those choosing to sell images through multiple agencies that each agency has different requirements and different markets (sometimes hard to learn). A rejection elsewhere doesn't mean rejection here and vise versa.
Learn to create good quality imagery and your image will get accepted, and hopefully 1 day you will sell the rights as well. It is well worth it.