The Company generates all of its revenue from contracts with customers. Many of the Company’s contracts with customers contain multiple performance obligations. For these contracts, the Company accounts for individual performance obligations separately if they are distinct. The transaction price is allocated to the separate performance obligations on a relative standalone selling price basis. Standalone selling prices of software licenses are typically estimated using the residual approach. Standalone selling prices of services are typically estimated based on observable transactions when these services are sold on a standalone basis. The Company usually expects payment within 30 to 90 days from the invoice date (fulfillment of performance obligations or per contract terms). None of the Company’s contracts as of March 31, 2019 contained a significant financing component. Differences between the amount of revenue recognized and the amount invoiced, collected from, or paid to its customers are recognized as deferred revenue.

The following table provides information about disaggregated revenue for the three months ended March 31, 2019 and 2018 by the timing of revenue recognition, and includes a reconciliation of the disaggregated revenue by reportable segment (in thousands):

	Three Months Ended
	March 31,
	2019		2018
Revenue
Software & Services
Products and services transferred over time	$	8,875	$	8,786
Products transferred at a point in time		2,283		1,899
Total Software & Services	$	11,158	$	10,685
Portal & Advertising
Products and services transferred over time	$	1,506	$	2,087
Products transferred at a point in time		19,160		20,143
Total Portal & Advertising	$	20,666	$	22,230
Total Revenue	$	31,824	$	32,915

Revenue disaggregated by geography, based on the billing address of our customer, consists of the following (in thousands):

	Three Months Ended
	March 31,
	2019		2018
Revenue
United States	$	26,274	$	27,038
International		5,550		5,877
Total revenue	$	31,824	$	32,915

Deferred revenue is recorded when cash payments are received or due in advance of revenue recognition from software licenses, professional services, and maintenance agreements. The timing of revenue recognition may differ from the timing of billings to customers. The changes in deferred revenue, inclusive of both current and long-term, are as follows (in thousands):

(in thousands)
Beginning balance - January 1, 2019	$	8,886
Recognition of deferred revenue		(3,319	)
Deferral of revenue		2,935
Effect of foreign currency translation		(300	)
Ending balance - March 31, 2019	$	8,202

The majority of the deferred revenue balance above relates to the maintenance and support contracts for Email software licenses. These are recognized straight-line over the life of the contract, with the majority of the balance being recognized within the next twelve months.

The Company generally expenses sales commissions when incurred because the amortization period would have been one year or less. These costs are recorded within sales and marketing expenses.

The Company does not disclose the value of unsatisfied performance obligations for (i) contracts with an original expected length of one year or less and (ii) contracts for which revenue is recognized at the amount to which the Company has the right to invoice for services performed.