Did you look carefully? I started with AT&T in May. I got rates good for 12 months, and it was clearly stated that the rates lasted only that long. That's what that little asterisk is for after the price you see:
$19.95 per month*
* Terms and Conditions
Offer available for new residential Internet customers only. Offer applies to up to 6.0 Mbps Internet service after monthly bill credit. After 12 months, standard rate applies unless canceled by customer. Requires AT&T home phone service. Promotional rates may no longer apply if customer changes their speed tier during term. Modem/gateway required. Taxes apply.
There is also a link to plan details which tells you what the non-discount rate is:
$19.95/mo. for a full 12 months with no term commitment. Save $23.05/mo. off the regular $43.00 price! That's a savings of over $276.
There is no need to ask if you click.