Each campaign is different, and each targeted audience calls for a new mix in both message and presentation. I like to think of the wide variety of available ad units in terms of sushi: There are lots of different styles, but only a few key families (i.e., sashimi, nigiri, rolls).
This sushi analogy can be useful in helping clients to plan campaigns. Instead of presenting clients that are less familiar with video with a flurry of industry jargon that includes pre-roll, mid-roll, post-roll, expandable, overlay, ticker, bumper, bug, interstitial, floating ad, takeover, etc., I find it useful to break things into a few simple families: in-stream, in-banner, and page-level (which includes units like interstitials, floating ads, and page takeovers). This way, you can unclutter your value proposition for potentially timid online video advertising customers, and leave them feeling that they've found the optimal ad mix for their marketing spend.
So what does this mean for the industry? As we move more and more toward flexible pricing models and hybrid video buys, standardization of terminology and education becomes a paramount issue when working with media buying partners. By presenting the potential formats as "families," it's easier to summarize the pros and cons for individual campaign buys. After that, it's easier to determine which "styles" will be most effective.
Let's look at a few of the high-level pros and cons associated with each of the families described above:
Well-understood (and most complementary) when compared to traditional television ads
Easy to develop if using existing television assets
Tends to have highest completed views and click-through rates
High engagement due to a "captured" audience
Tends to receive user backlash due to intrusiveness
Repurposed television ads may not be best-suited for this purpose
Inventory is generally more expensive than display inventory
Easy-to-find, relatively inexpensive display inventory
Can be easily sold on a performance basis
Relatively unintrusive (as long as it doesn't auto start with sound)
Offers many opportunities for rich-media customization
Often not as engaging as in-stream or page-level
May not be seen if appearing below the fold
If trafficked via an exchange, may not provide desired transparency into site placements
Affords tremendous potential for creative freedom
Offers lots of flexibility for rich media customization
Great for building awareness and other top of funnel metrics
Can be quite expensive, depending upon where it's being run
If not user-initiated, can be very intrusive and annoying to the user
May require considerable design work
In summary, the online video advertising world is changing. It's more flexible, diverse and rife with opportunities -- but media buyers can only take advantage of this more favorable atmosphere if they can clearly understand the benefits and downfalls of all their purchase elements. In this increasingly complex world of video ad unit formats, let's start with the "sushi roll" before diving into the "tempura shrimp wrapped in grilled unagi and avocado."