Just how many small business are out there?

I thought this was pretty interesting, although from 2007 (would love to see the final 2010 numbers when they are released) it offers a glimpse at the small, medium and enterprise scale businesses operating in the United States. This is pretty useful when you are trying to look at total available  markets (TAM) or other indicators around businesses, employee counts, etc.

Employment Size of Firms

Table 2a. Employment Size of Employer and Nonemployer Firms, 2008
Introductory text includes scope and methodology. These data are also available by industry and state. Table includes both establishments with payroll and nonemployers. For descriptions of column headings and rows (industries), click on the appropriate underlined element in the table.
Employment size of enterprise Firms Estab-
lish-
ments		 Paid
employees		 Annual
payroll
($1,000)		 Sales or
Receipts
($1,000)
n/a – Receipts data are available for employers only for the years for which an economic census is taken (2007, 2002, 1997).
All firms 27,281,452 28,952,489 120,903,551 5,130,509,178 n/a
Nonemployer firms 21,351,320 21,351,320 n/a n/a 962,791,527
Employer firms 5,930,132 7,601,169 120,903,551 5,130,509,178 n/a
Firms with 1 to 4 employees (or with no employees as of Mar 12) 3,617,764 3,624,614 6,086,291 232,062,907 n/a
Firms with 5 to 9 employees 1,044,065 1,056,947 6,878,051 222,504,912 n/a
Firms with 10 to 19 employees 633,141 667,463 8,497,391 293,534,352 n/a
Firms with 20 to 99 employees 526,307 705,430 20,684,691 774,589,335 n/a
Firms with 100 to 499 employees 90,386 359,902 17,547,567 706,476,693 n/a
Firms with 500 employees or more 18,469 1,186,813 61,209,560 2,901,340,979 n/a
Firms with 500 to 749 employees 6,060 72,676 3,681,760 156,491,764 n/a
Firms with 750 to 999 employees 3,038 48,005 2,617,087 114,635,897 n/a
Firms with 1,000 to 1,499 employees 3,044 64,556 3,720,654 167,658,791 n/a
Firms with 1,500 to 1,999 employees 1,533 45,062 2,653,392 121,800,728 n/a
Firms with 2,000 to 2,499 employees 904 36,081 2,011,244 94,406,916 n/a
Firms with 2,500 to 4,999 employees 1,934 120,416 6,726,611 329,188,349 n/a
Firms with 5,000 employees or more 1,956 800,017 39,798,812 1,917,158,534 n/a
Firms with 5,000 to 9,999 employees 975 121,835 6,773,466 337,598,036 n/a
Firms with 10,000 employees or more 981 678,182 33,025,346 1,579,560,498 n/a

Taken From the US Census: http://www.census.gov/econ/smallbus.html#EmpSize