I have uploaded all of mine in jpg format also.
Technically, jpg files are supposedly a little worse in quality than bmp files, however, if you utilize a fairly low compression ratio in converting your bmp files to jpg files, or if you origianlly save your images in jpg format, I am fairly certain that even the most eagle-eyed would be completely incapable of differentiating between the two. The jpg format is the standard one used for almost all image files that can be downloaded from websites, as the, to most all eyes, indistinguishable quality difference hardly justifies the immense disparity in file size.