Is Runway good for e-commerce product shots?

For an internal sketch, yes. For a catalog of final stills, it does not compete: framing, material and background iteration is cheaper and faster in Midjourney, and high-res export is built for images, not for pulling a frame from a video engine.

Which one for key art on a spot that will be animated later?

Generate the key art in Midjourney: you control light, framing and style. Import the PNG into Runway only when the still already holds and you want to test a gesture or camera move. Do not generate key art directly in Runway unless it is a one-off single-frame prototype.

Can I do concept art with Runway only?

You can, but you will spend video credits on every exploration. Midjourney is built to vary a concept in a grid: same scene, different camera, different stylize. For concept art that will not be animated, that flow wins.

How is this different from the general Midjourney vs Runway comparison?

The general comparison covers still + clip and when to move from image to motion. This page only compares when the deliverable is a fixed image: product shot, key art, campaign still or concept art. If your plan includes video, start here for the still, then read the other for the clip.

Runway vs Midjourney for stills

Fixed images only: product shots, key art, campaign stills and concept art. No clips or motion.

	Runway	Midjourney
Product shots	Fine as a sketch; little iteration on framing and light	Very high: subject, material and background when the prompt describes the shot
Key art and campaign stills	A loose frame; no moodboard or coherent series	Grids, variations and --sref for a campaign look in series
Concept art	Fast for one idea; quality below a dedicated image engine	Style, camera and palette exploration in minutes
Final still export	Frame pulled from the video flow; resolution capped by the model	Upscale and high-res download from the grid
Iteration per deliverable	Each image spends credits shared with Gen-3 and motion	Remix, vary region and variations with no video tax
Keyframe before animating	Native: the still lives in the same project as the clip	Better still, but you must import the PNG into Runway after
Risk on a stills brief	Video budget burned on images that will never be animated	Generic look if the prompt is vague; minutes on refinement
Do not use for	A 30-shot product catalog with no motion pass	A 4–8 s clip (there is another comparison for that)

Verdict

If the deliverable is a still — product shot, reference keyframe, marketing frame or concept art that will not be animated — Midjourney wins: grids, variations and high-res export are built for that. Runway can output a frame, but each attempt competes with video credits and look iteration is slower. Use Runway for stills only when you already have a motion project open and need a starting frame in the same session before animating; for a catalog of fixed images, do not mix engines. If you will animate the keyframe, read midjourney-vs-runway then runway-primer-clip.