How sexy are you? Rate yourself how attractive you are to the opposite sex (or same sex for non-traditional folks) - be honest. Now take that number and add/subtract 2 from it. There are many who would suggest that you should not marry anyone outside that range - the experiences you have in life, and the type of person that it makes you, will create too big a rift for you to overcome over time (this does not apply to shorter term relationships).
It is my opinion that this rule of thumb is not just correct, but is mostly correct along any axis - how attractive you are, how much money you have (or grew up with), how much education you have (e.g. Ph.D vs. high school diploma), level of religious dedication (e.g. baptized vs. non-practicing) and so on. It's just the kind of thing that starts off seeming small, but, over time, slowly grinds away at an otherwise healthy relationship and makes things a lot harder than it should be. Unless people are on the same page, it's just one more blocker in the already hard road to happiness. It's not to say it can't be done, but it's important to be aware of the difficulty you're going to face when you go against this rule.
A similar guideline applies when deciding who to work with in your business. Any time you work outside your class you're going to face endless difficulties. The most common situation is a small company working with a large one, but that friction can be present with any organization that is significantly different than yours. Here are some things to pay attention to:
- Speed of execution - Are you iterating every other week? Does your potential partner need fourteen layers of approval to launch a Web site?
- Size of impact of the deal - Is this deal going to make or break your business? Will your deal even move the needle for your partner's bottom line?
- Ability to resource - Is your entire organization ready to work on closing the deal? Does your partner have even one head attached?
- Timing on payments/exchange of value - Do you need the deal to close next week to make payroll? Is your partner net three years?
The key is understanding how to mitigate the issues. For example, if they're net 120 and you need the money to manage campaign tomorrow - you need to find (and set aside the money) from somewhere else and be ready to give those dollars for the duration. No resources at the partner? Assign people on your team to step in and help it along. These steps almost always will make you slower, but over extending yourself is a recipe for disaster. And the further away the firm from your place on the axis, the more leeway you need for your buffer time, money and resources to vary wildly.
Of course, if you find your true love, you don't just walk away. It's possible to make your partnerships work, even if you're way apart to start. But be honest with yourself and the situation - if you think it's going to be easy to work out of your league, you're in for heartbreak.