Every once in a while you will have a print-ready PDF that you need to modify. For the most part, this is pretty easy; however, if you want to insert a vector graphic, there’s no straightforward mechanism – the “Add Image” only works with raster images, which look like crap if you are working on a hi-res or print design.
The trick is actually surprisingly simple – just open the EPS as a PDF > Edit PDF > Select All > Copy > Paste into the original PDF
This will copy the shapes, maintaining their vector properties, so you can then scale with no degradation of quality. The one thing to watch out for is that Acrobat may try to convert your EPS to text via OCR – just make sure you decline this when prompted.