Originally posted a long reply to wayn3, but decided there's little point.
All I'll say is that a truly amazing developer is worth a hell of a lot to a web based company building a product, and that an amazing developer fits in neither of his two categories that "all developers" fall into, and that the only way you'll get them onboard is by giving them equity. Cas they can make serious bank somewhere else. (e.g. Algorithmic Trading in an investment bank). I'm not talking about your average self taught php developer, or an indian dev you found on ODesk.
If you're moronic to give someone 40% or 30% of your company upfront, you deserve to fail.
That's the whole reason vesting exists. Everyone on the team should be vested. Over at least 4 years. i.e. if you're going to own 40% of the company, you get 10% at the end of year 1, then an additional 0.833333% each month onwards for the next 3 years, until you're at your full 40%. That way, if someone wants to walk away or do something else, you're not fucked. The only person against something like this, is someone who is flaky in nature anyway, and worth avoiding.
In the web world, the worst people I've encountered are "business" people who have seen Facebook skyrocket, have an idea and money for a new product, and are looking for a coding monkey to implement it for them. They hire a developer (or outsource it to an agency), aren't willing to give any kinda equity and then wonder why their product is crap, or have no idea what to do when it breaks 6 months down the road.
Whilst lots of developers are tech motivated, and will build projects for the sake of using cool tech, there are developers out there with sound business heads on them. I'd very much consider myself a developer turned tech entrepreneur, who's acquired other skillsets as he's gone on. I'm now much of an online generalist. I'm no amazing developer, but I know how to spot one, and I know how to work with one. I'm not the best marketer either, but I could definitely identify one and again, work with one. Same goes for many positions involved in tech.
Most people often forget that having a partner is actually a key ingredient to success.
Why Do Startups Fail? An Analysis of 3,200 High-growth Technology Startups | Brilliant Forge
Some key points:
Solo founders take 3.6x longer to reach scale stage compared to a founding team of 2 and they are 2.3x less likely to pivot.
Business-heavy founding teams are 6.2x more likely to successfully scale with sales-driven startups than with product-centric startups. (i.e. if you're building a product, you need a tech heavy founding team with
equity. If you're just building an affiliate site, then you don't need tech, it's all about sales and marketing.)
Technical-heavy founding teams are 3.3x more likely to successfully scale with product-centric startups without network effects than with product-centric startups with network effects. (Founding teams that are tech heavy are more successful in growing businesses which don't suffer from network effects, so if you're building something like bufferapp.com, ifttt, google, etc.. A tech heavy team is much better than a business heavy team. However if you're building the next Facebook (huge networking effects), then the marketing strategy and business side is much more important)
Balanced teams with one technical founder and one business founder raise 30% more money, have 2.9x more user growth and are 19% less likely to scale prematurely than technical or business-heavy founding teams.
Most successful founders are driven by impact rather than experience or money.
In the end you need to build a team suitable for what you're doing, and people that are vital components of the business should all have equity. Everyone should be vested, even yourself. So that if you want to leave, the other founders can replace you and keep on working.
If you're serious about this then it's vital a solicitor draws this up for you. A solicitor experienced in vesting and company formations.
Generally speaking if there's a personX in your team that you think "what the fuck would I do without personX?" then they should have equity.