How do you justify the amount of sales enablement support you put behind different products?

The ultimate goal of sales enablement is to make sure the sales team is equipped to sell but also, they should “sell what's on the truck.” You can use the same mental model to justify the amount of sales enablement as you do when prioritizing:
1) Where are the biggest areas of opportunity? Are there any specific products or use cases where we are differentiated and we have a clear runway of opportunity? We should prioritize our efforts here.
2) Are there some products that are just ‘easier’ to sell? We should give our sales team the opportunity to get some quick wins in. They run on a commission basis so make them happy by giving them some 'easy to close' opportunities out of the gate.
3) Are there emerging product areas, or a market that your company wants to break into and you need to generate energy and excitement around? If yes, then this should also be an element you consider.

A couple of factors come to mind here. In general, consider what stage of the product lifecycle a particular product is in. That is usually a key factor that will inform the volume of sales enablement support you provide.

Another factor to take into account is which product have largest business/revenue opportunity in terms of TAM and growth potential? Most companies have a view on this as budgeting and resourcing decisions (beyond product marketing) have to be made from a top-down level.  

So it's important that sales enablement support efforts are roughly in line with how the company views different products from a business priority POV.  

This is a similar question to another one so sharing the same answer :) 

 The best way in my opinion is to zoom out and look at it through the lens of the company's main goals (usually revenue goals). Are those areas being served well? And prioritize from there.

Also, where are there the biggest knowledge gaps? You have to be careful on this one though since while there may be a knowledge gap in one space if reps are not going to prioritize that space, it will likely be wasted effort. So alignment with the business goals and sales strategy/level of rep mindshare you will get is critical and key. 

I always start with the outcome that matters to the company then back out what needs to happen to drive that outcome. For example, if we need to launch a product that drives XYZ in revenue over the first year, I will try to back out how much pipeline is needed and what kinds of win rates need to happen in order to hit that goal. From there, I will focus on the exact metrics that PMM can directly impact (often win rates, with some collaboration with Demand Gen / Growth Marketing on pipeline generation) then back out what's needed to get those metrics to what we think we need. For example, if we're targeting win rates, I'd keep a close eye on win/loss data and try to identify what kinds of messaging or competive positioning is going to move the needle to help get us to the right win rate. 

Ultimately, having good data, both qualitative and quantitative on what activities drive results allows me to clearly point out what value I've been able to add and justify the investment in sales enablement.

This is a great question. I would start by deconstructing the enablement initiative in the following ways to justify support:

1. Assess product impact, demand, and revenue potential.

2. Address sales team needs and skill gaps.

3. Consider product complexity and competitive landscape.

4. Estimate ROI and revenue contribution.

5. Prioritize value proposition and messaging alignment.

6. Support new product launches strategically.

7. Seek sales team feedback for enablement needs.

8. Strive for balanced resource allocation.

A launch tiering exercise could also dictate how much time is spent educating the team - thresholds for tiers 1-2 receive support while 3-4 (lower impact) do not.