In an effort to convince startups to adopt the cloud — and by extension, eventually be profitable customers — the big three public cloud providers are offering six-figure discounts to startups working with approved startup accelerators and incubators. Smaller discounts are available to independent projects or developers learning to work with cloud platforms.

Microsoft Azure and BizSpark Plus

Microsoft’s BizSpark program (the counterpart to the DreamSpark program for university students) offers $10,000 per month of Azure cloud services to BizSpark Plus for one year — for a total of $120,000. Eligibility is dependent on collaboration with a startup accelerator, with Microsoft partnering with over 150 startup accelerators in 47 countries, according to the announcement on Microsoft Developer Platform VP Steve Guggenheimer’s blog.

For smaller startups not aligned with a startup accelerator, the standard-tier BizSpark is available to privately-held companies less than five years old that earn less than $1 million USD annually. The standard tier provides up to $750 per month ($150 per month for up to five developers) for three years for a total of $27,000. Both tiers are eligible for free access to other software and services from Microsoft, including licenses for Windows, Office, and Visual Studio.

In an interview with Fortune, Mark Russinovich, the CTO of Azure, noted that “one out of five virtual machines hosted on Azure runs Linux,” which is an important consideration as part of Microsoft’s recent embrace of open-source software under CEO Satya Nadella.

Amazon Web Services Self-Starter and Portfolio packages

Like Microsoft, Amazon has different free tiers for startups. The Portfolio Plus package provides up to $100,000 of promotional credit for AWS for one year. The Portfolio and Portfolio Plus packages also offer up to $15,000 of promotional credit for up to two years, though the exact amounts and times vary between different startup accelerators. The promotional credit can be applied to most AWS services (except for the Mechanical Turk crowdsourcing platform), some types of support, services offered on the AWS Marketplace, or upfront payments for Reserved Instances.

The AWS Free Tier is available to anyone without restriction for the first 12 months. It features 750 hours per month of EC2 t.2 micro instances of Linux (including RHEL and SLES) or Windows, which can be run as one instance at a time or as multiple simultaneous instances. The free tier also includes 5 GB of standard storage in S3, with 20,000 GET and 2,000 PUT requests and 25 GB of storage in DynamoDB with 25 units of Write and Read capacity each, which Amazon estimates to be sufficient to handle 200 million requests per month. It also includes one million free requests in Lambda, and 20,000 free requests in AWS Key Management, and free access grants in one dozen other AWS services.

Google Cloud Platform for startups

Google’s initiative for startup access grants potential users $100,000 in Cloud Platform credit, which can be used for up to a year, and applies to all of the products offered by Google Cloud Platform. Like Amazon and Microsoft, applicants must be working with an approved accelerator or incubator. Google’s requirements stipulate that applicants must have less than $500,000 in annual revenue, and less than $5 million in funding.

Unlike Microsoft and Amazon, Google doesn’t have a free tier for smaller projects not aligned with a startup accelerator or incubator.

Whose cloud are you on?

Does the prospect of cloud credits make cloud computing more attractive for your organization? Would you remain with a cloud vendor that provided account credits, even after those credits ended? Or, would you move your workload to a cheaper vendor?