This is a really great question.

It's not necessarily bad to be a middleman, but your intuition is correct — if you can move move downstream and directly tie into the value a customer gets, your customers are less likely to cancel/move out of your coworking space.

I'd think about this in three ways...

1) What are COMPLIMENTARY services you can offer your customers? In other words, what else do your customers need? The immediate thought for me are startups and SMEs always want more help growing their business. If you can give them a network of experts — like maybe access to a law professional 1x per week, an email marketing expert 1x per week, etc. — during physical or virtual office hours, that could be a huge benefit. Think about WeWork... it's not just about the space, it's about the benefits and network.

2) I think partnerships, in general, are highly underutilized but extremely beneficial. Think of all the local businesses in the area of your coworking spaces. Can you offer them gym discounts? Discounts to the local FedEx Kinko's for shipping and scanning? Most local businesses are desperate for customers, so the odds of getting a deal and increasing your footprint are easier than one typically thinks.

3) Ask your customers! When they signup or join, ask them what's the #1 thing they're struggling with their business. Most people are bad at telling you what they want (the great book "Ask" talks about this), but are GREAT at saying what they don't want, or their bad experiences in the past. Asking them their #1 frustration makes it easier than an answer to get their top 10. I'm not of the belief that the customer knows everything — you'll have to read between the lines sometimes and make some educated guesses — but it can help you sometimes get pointed in the right direction.

Hope this helps! If you have any follow-up questions, happy to jump on an hour call. We built an 8-figure online company by building complimentary products, so I'm familiar with how this is approached.