Sometimes when I illustrate, my EPS file gets too big (around 50MB or more) and that's one thing you can avoid happening.
For better compatibility I save my vector files as EPS 8, so after the original AI file is finished try to shrink the size of the file this way:
- Click Save As (choose EPS)
-A new dialog box appears and you choose the Version: Illustrator 8 EPS (for best compatibility)
-Choose the Preview Format to NONE (this will decrease the size of it quite a bit)
-Now uncheck Embed fonts
-Uncheck Include Document Thumbnails
Now click OK, that should do it.
NOTE: If your vector contains transparency objects when you save EPS 8 you'll have to check the Preserve Appearance and Overprints (in the same dialog box) and that usually rasterizes a part of your vector and increases its sizes a lot, not to mention it reduced editability and quality, so if you have a lot of transparency effects in your file it's more practical to upload the AI file as additional format instead of an EPS 8.